Silicon-based gallium oxide erbium-ytterbium doped electroluminescent device capable of realizing population inversion

Abstract

The invention discloses a silicon-based gallium oxide erbium-ytterbium doped electroluminescent device capable of realizing population inversion. The silicon-based gallium oxide erbium-ytterbium doped electroluminescent device comprises a metal electrode, a silicon layer, a luminescent layer and a transparent conductive electrode which are arranged in sequence, the light-emitting layer comprises gallium oxide ytterbium-doped layers and gallium oxide erbium-doped layers which are arranged alternately. Due to interaction between erbium and ytterbium ions, a large number of electrons are excited to be above an excited state energy level, inversion of redundant ground state electrons on the excited state energy level can be achieved under a certain current, and population inversion on an Er < 3 + > energy level is a necessary condition for achieving silicon-based erbium-doped electro-laser. The device prepared by the invention provides a theoretical and experimental basis for the realization of silicon-based erbium-doped electro-laser.

Description

Technical Field

[0001] The invention relates to the technical field of silicon-based electroluminescence, and in particular to a silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of realizing particle number inversion. Background Art

[0002] With the rapid development of microelectronics technology, the number of transistors on a single chip is increasing. Problems such as signal delay, heat release and signal interference caused by metal wire interconnection are becoming increasingly serious. Since photons transmit at high speeds and with low losses, using photons as a carrier for transmitting information can effectively solve the above problems, and it has gradually become an inevitable trend in the development of integrated circuits.

[0003] In order to realize the transmission of information by photons, a complete silicon-based optoelectronic system needs to be prepared. At present, people have made great progress in silicon-based optical waveguides, optical signal modulators, optical signal amplifiers, and optical signal detectors, but have not yet achieved efficient silicon-based light emission. 3+ ) has a characteristic luminescence peak of ~1540nm, which is located in the window with the lowest optical fiber loss and is compatible with the existing CMOS process, and has always been a hot topic of research. 3+ In terms of doping matrix, people have tried silicon, insulating compounds of silicon such as silicon oxide, silicon nitride, silicon oxynitride and erbium silicate, and narrow bandgap semiconductors such as gallium arsenide and indium phosphide. However, these matrices have serious luminescence quenching at room temperature, high turn-on voltage, low luminescence efficiency, etc., making them difficult to put into practical application. In this context, common metal oxides such as zinc oxide, titanium oxide, gallium oxide, etc. are considered suitable Er due to their suitable band gap and excellent stability. 3+ Doped matrix. For example, Yang, Y., et al., Low-voltage driven visible and infrared electroluminescence from light-emitting device based on Er-doped TiO 2 / p + -Si heterostructure.AppliedPhysics Letters,2012.100(3):031103 completed the doping of erbium in the titanium oxide matrix. 20 cm -3 At the same time, the turn-on voltage of the device is kept below 10V.

[0004] In Er 3+In terms of excitation mechanism, although the common hot carrier luminescence device has a simple structure and is easy to implement, it requires high voltage to generate hot carriers and involves a collision process. Therefore, the device has a high turn-on voltage and poor stability, making it difficult to put into practical application. 3+ Energy transfer between 3+ This method has low turn-on voltage and excellent stability. For example, Pang, H., et al., Near-infrared luminescence of erbium doped Ga 2 O 3 films and devices based on silicon: Realization of energy transfer.Optical Materials, 2022.129:112462, namely, using oxygen vacancy-related recombination in gallium oxide matrix to excite Er 3+ , realizing silicon-based electroluminescence.

[0005] Although in Er 3+ Some progress has been made in the doping matrix and luminescence mechanism of erbium-doped luminescent devices, but the luminescence process of electroluminescent devices based on energy transfer is relatively complex and the intensity is relatively low. In addition, in practical applications, silicon-based optoelectronic systems need lasers with better luminescence performance, and in erbium-doped luminescent devices, the supercarrier transfer in Er has not yet been achieved. 3+ The inversion of energy levels cannot meet the necessary conditions for laser generation.

[0006] Therefore, the current bottleneck of erbium-doped silicon-based electroluminescent devices is that the luminous intensity of the prepared devices is too low to meet actual needs. Moreover, it has not yet been achieved that Er 3+ The inversion of the number of particles in the energy levels cannot meet the necessary conditions for the realization of lasers, making it difficult to achieve electro-laser.

[0007] Aiming at the shortcomings in the art, namely, ① the Er of the prepared silicon-based oxide doped erbium electroluminescent device 3+ ① The luminous intensity is low and it is difficult to actually apply it to applications; ② It is difficult to realize Er in silicon-based erbium-doped devices under point injection conditions. 3+ The number of particles on the energy level is inverted, and the conditions for realizing laser cannot be met. Therefore, the present invention proposes a new gallium oxide erbium ytterbium doped multilayer device structure. At present, there is no method for using ytterbium ions (Yb) in erbium-doped gallium oxide. 3+) doped layer to prepare quantum well structure and realize population inversion. Yang Y.,et al.,Energy transfer under electrical excitation and enhanced electroluminescence in the nanolaminate Yb,Er co-doped Al 2 O 3 films.Physica Status Solidi-Rapid Research Letters,2019,13(8):1900137 in Al 2 O 3 In the 1990s, silicon-based electroluminescence was achieved by co-doping erbium and ytterbium, but the luminescence in this device mainly relies on hot carriers under high electric fields, so the operating voltage of the device exceeds ~60V, which is difficult to put into practical application. In addition, the Al 2 O 3 、Al 2 O 3 / TiO 2 The layers are all high-resistance layers, so the current flowing through the device is extremely low, and it is difficult to provide sufficient carriers to achieve Er 3+ The particle number inversion at the energy level does not realize the quantum well type energy band structure, which is contrary to the original intention of the present invention to realize the particle number inversion and the enhancement of the luminous intensity at the same time at a low voltage.

[0008] In the device designed by the present invention, Yb 3+ Xiang Er 3+ Energy transfer and electron transfer make Er 3+ There are more particles in the excited state energy level, and the number of excited state particles is greater than that of the ground state at a lower excitation current, which can increase Er 3+ In addition, multilayer devices will form a quantum well-type energy band structure, which will make the electrons more confined to the Er-doped 3+ in the light-emitting layer, thereby increasing the luminous intensity. Summary of the invention

[0009] The purpose of the present invention is to improve the luminous intensity of silicon-based gallium oxide doped erbium devices based on energy transfer and simultaneously achieve Er at a lower current 3+ The inversion of the number of particles at the energy level provides theoretical and experimental support for the realization of silicon-based erbium-doped electrolaser. The present invention found that when a gallium oxide-doped ytterbium layer of appropriate thickness and concentration is introduced into the silicon-based gallium oxide-doped erbium film, Yb 3+ , Er 3+ Energy transfer and electron transfer will occur simultaneously between 3+The realized 980nm radiation will be transferred to Er 3+ , stimulate Er 3 + Achieve ~1540nm emission, and Yb 3+ middle 2 F 5 / 2 The electrons on the energy level will be transferred to Er 3+ middle 4 I 11 / 2 energy level, and then jump down to 4 I 13 / 2 As the device current increases, Er 3+ middle 4 I 13 / 2 The number of electrons on the energy level is greater than 4 I 15 / 2 The number of electrons in the ground state realizes Er 3+ The number of particles on the energy level is reversed, and the luminescence intensity is increased by energy transfer. 3+ The incorporation of Yb can effectively reduce the band gap of gallium oxide. 3+ When the gallium oxide doped ytterbium layer is placed on both sides of the gallium oxide doped erbium layer, a quantum well type band structure can be prepared, and the electrons will be more confined in the gallium oxide doped erbium light-emitting layer, effectively increasing Er 3+ Luminous intensity.

[0010] [1] The present invention provides a silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, comprising a metal electrode, a silicon layer, a light-emitting layer and a transparent conductive electrode arranged in sequence;

[0011] The light-emitting layer includes gallium oxide doped with ytterbium layers and gallium oxide doped with erbium layers which are arranged alternately.

[0012] When a positive bias is applied to the silicon / gallium oxide device, Yb in the erbium-doped gallium oxide and ytterbium-doped gallium oxide layers 3+ , Er 3+ All are excited, Yb 3+ middle 2 F 5 / 2 The wavelength of the transition between the excited state and the ground state is ~980nm, which is exactly the same as the wavelength of Er 3+ The ground state and 4 I 11 / 2 The energy level difference between the states matches, so Yb 3+ The energy from radiative recombination can be transferred to Er 3+ , Yb 3+ Acts as a sensitizer to increase Er 3+ In addition, due to the Yb 3+ , Er 3+ The 4f excited state energy levels are close to each other, so Yb3+ The electrons in the excited state can be transferred to Er 3+ The excited state energy level increases Er 3+ The number of electrons in the excited state energy level makes more Er 3+ In an excited state, electron transfer is achieved. 3+ , Er 3+ Energy transfer and electron transfer between them can achieve Er at a lower current 3+ The inversion of the number of particles on the energy level and the increase of Er 3+ The luminescence intensity. The quantum well structure of ytterbium / erbium / ytterbium will further increase the 3+ Luminous intensity.

[0013] In order to achieve efficient energy transfer and electron transfer, it is necessary to ensure that Er 3+ , Yb 3+ The number of matches and the distance is moderate. 3+ , Yb 3+ In terms of quantity, the Er in the multilayer structure can be changed by adjusting the thickness of the erbium-doped gallium oxide and the ytterbium-doped gallium oxide layers. 3+ , Yb 3+ In the present invention, the thickness ratio of the gallium oxide doped with erbium and the gallium oxide doped with ytterbium can vary in the range of 1:0.5-2, wherein when the thickness ratio is 1:1, Er 3+ , Yb 3+ The quantity matches, and the transmission and transfer effects are the best. 3+ , Yb 3+ In terms of spacing, the number of layers can be adjusted to change Er 3+ , Yb 3+ In the present invention, the total thickness of the layers can vary in the range of 2-6 layers, wherein when the layers are 3 layers, Er 3+ , Yb 3+ Appropriate spacing ensures the highest transmission and transfer efficiency.

[0014] In addition to the microscopic interactions between rare earth ions, by setting up a suitable multilayer structure, the different band gaps between the gallium oxide doped with erbium and gallium oxide doped with ytterbium can be used to prepare a quantum well structure. 3+ The concentration is lower, so its band gap is wider. If the erbium-doped gallium oxide of the light-emitting layer is confined between the gallium oxide-doped ytterbium layers on both sides, a wide band gap / narrow band gap / wide band gap quantum well structure can be prepared. This structure can confine electrons in the light-emitting layer, which is similar to Er. 3+ , Yb 3+ The interaction between them jointly improves the luminescence intensity of the device.

[0015] In the silicon-based gallium oxide erbium ytterbium doped electroluminescent device that can achieve population inversion of the present invention, the metal electrode, silicon layer, and transparent conductive electrode can all adopt existing technologies. For example, the metal electrode can be gold, silver, copper, aluminum, etc., and the transparent conductive electrode can be indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO), etc. The thickness of the metal electrode and the transparent conductive electrode can be adjusted as needed by those skilled in the art. For example, the thickness of the metal electrode and the transparent conductive electrode can be about 100nm.

[0016] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, the total number of gallium oxide doped ytterbium layers and gallium oxide doped erbium layers in the light-emitting layer can be 2-6 layers, for example, 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, preferably 3 layers. Under the premise of ensuring the total thickness, the appropriate number of layers can make Er 3+ , Yb 3+ The distance between ions is appropriate to ensure efficient energy transfer and electron transfer. When the number of layers is too small, the distance between ions is too far and the transfer efficiency is low; when the number of layers is too large, the distance between ions is too close and energy will be lost during the transfer between ions. In general, 3 layers is the optimal number of layers.

[0017] In some preferred examples, the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, the light-emitting layer comprises two gallium oxide doped ytterbium layers and a gallium oxide doped erbium layer located between the two gallium oxide doped ytterbium layers. In the three-layer structure of gallium oxide doped ytterbium / gallium oxide doped erbium / gallium oxide doped ytterbium, Er 3+ , Yb 3+ The spacing is appropriate, and the efficiency of electron transfer and energy transfer is higher. In addition, due to the Yb 3+ The concentration is lower and the band gap is wider, so the above three-layer structure will form a wide band gap / narrow band gap / wide band gap quantum well structure, which can effectively confine electrons in the gallium oxide doped erbium light-emitting layer with a narrower band gap, thereby improving the luminescence intensity of the device.

[0018] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, in the light-emitting layer, the thickness of the gallium oxide doped ytterbium layer and the gallium oxide doped erbium layer may be independently not less than 10 nm, and further independently not less than 15 nm.

[0019] In some preferred embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, in the light-emitting layer, the ratio of the total thickness of all gallium oxide doped ytterbium layers to the total thickness of all gallium oxide doped erbium layers is 1:0.5-2, and more preferably 1:1. Under this thickness ratio, Er 3+ , Yb 3+ Quantity balance, avoiding Yb 3+The number is too small, for Er 3+ The regulatory effect is limited; it also prevents 3+ The quantity is too small and the luminous intensity is too low to fully accept Yb 3+ Therefore, when the thickness ratio of gallium oxide doped with erbium and gallium oxide doped with ytterbium is 1:1, it is most suitable for luminescence.

[0020] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, in the gallium oxide doped ytterbium layer, the atomic concentration of ytterbium may be 0.1%-2%, for example 0.2%, based on the total atomic number of gallium and ytterbium being 100%.

[0021] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, in the gallium oxide doped erbium layer, the atomic concentration of erbium may be 0.5%-5%, for example 2%, based on the total atomic number of gallium and erbium being 100%.

[0022] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, the light-emitting layer can be obtained by annealing after forming alternating gallium oxide doped ytterbium layers and gallium oxide doped erbium layers by radio frequency magnetron sputtering. The atmosphere of radio frequency magnetron sputtering can be a rare gas (such as argon, etc.) atmosphere, etc. The atmosphere of the annealing can be nitrogen, oxygen, a rare gas (such as argon, etc.), etc. The temperature of the annealing is preferably above 700°C, and the time is preferably not less than 5 minutes, for example, 2 hours, etc.

[0023] The RF magnetron sputtering can use a gallium oxide doped ytterbium target to prepare a gallium oxide doped ytterbium layer. Further, based on the total number of gallium and ytterbium atoms in the gallium oxide doped ytterbium target being 100%, the atomic concentration of ytterbium in the gallium oxide doped ytterbium target can be 0.1%-2%, for example 0.2%.

[0024] The RF magnetron sputtering can use the gallium oxide doped erbium target to prepare the gallium oxide doped erbium layer. Further, based on the total number of gallium and erbium atoms in the gallium oxide doped erbium target as 100%, the atomic concentration of erbium in the gallium oxide doped erbium target can be 0.5%-5%, for example 2%.

[0025] The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion of the present invention has a turn-on voltage of less than 10V, and can achieve population inversion of erbium ions at the energy level under a current of 2.0 mA. Specifically, when a positive bias is applied to the silicon / gallium oxide heterojunction, the silicon-based gallium oxide erbium ytterbium doped electroluminescent device has a turn-on voltage of less than 10V, and can achieve population inversion of erbium ions at the energy level under a current of 2.0 mA. 3+ The excitation lifetime begins to be lower than the decay lifetime, which corresponds to the probability of electrons being excited to the excited state being higher than the probability of decaying back to the ground state, that is, the reversal of the number of particles in the excited state being higher than that in the ground state is achieved.

[0026] [2] The present invention provides a method for preparing a silicon-based gallium oxide erbium ytterbium doped film, using a radio frequency magnetron sputtering system. The preparation method comprises: alternately sputtering a gallium oxide doped ytterbium layer and a gallium oxide doped erbium layer on a clean heated silicon substrate, and annealing after sputtering to obtain the silicon-based gallium oxide erbium ytterbium doped film.

[0027] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, the total number of gallium oxide doped ytterbium layers and gallium oxide doped erbium layers may be 2-6 layers, such as 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, preferably 3 layers. 3+ , Yb 3+ The moderate spacing can ensure efficient energy transfer and electron transfer.

[0028] In some preferred examples, the silicon-based gallium oxide erbium ytterbium doped film includes two gallium oxide doped ytterbium layers and a gallium oxide doped erbium layer located between the two gallium oxide doped ytterbium layers. This gallium oxide doped ytterbium / gallium oxide doped erbium / gallium oxide doped ytterbium structure can form a wide band gap / narrow band gap / wide band gap quantum well structure, so that electrons are confined in the light-emitting layer, and the Er 3 + , Yb 3+ The interaction between them increases the Er 3+ luminous intensity.

[0029] In the silicon-based gallium oxide erbium ytterbium doped thin film, the thickness of the gallium oxide doped ytterbium layer and the gallium oxide doped erbium layer may be independently no less than 10 nm, and further independently no less than 15 nm.

[0030] In some preferred embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, the ratio of the total thickness of all gallium oxide doped ytterbium layers to the total thickness of all gallium oxide doped erbium layers is 1:0.5-2, and more preferably 1:1. At a thickness ratio of 1:1, Er 3 + , Yb 3+ The quantity ratio is balanced, Er 3+ The light itself is strong enough to accept Yb 3+ The energy and electrons transferred.

[0031] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, in the gallium oxide doped ytterbium layer, based on the total number of gallium and ytterbium atoms being 100%, the atomic concentration of ytterbium may be 0.1%-2%, for example, 0.2%.

[0032] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, in the gallium oxide doped erbium layer, based on the total number of gallium and erbium atoms being 100%, the atomic concentration of erbium may be 0.5%-5%, for example, 2%.

[0033] In some embodiments, in the method for preparing the silicon-based gallium oxide erbium ytterbium doped thin film, the silicon substrate heating temperature may be above 150°C, preferably not exceeding 300°C.

[0034] In some embodiments, in the method for preparing the silicon-based gallium oxide erbium ytterbium doped thin film, the atmosphere of the radio frequency magnetron sputtering can be a rare gas (such as argon, etc.) atmosphere.

[0035] In some embodiments, in the method for preparing the silicon-based gallium oxide erbium ytterbium doped thin film, the annealing atmosphere can be nitrogen, oxygen, a rare gas (such as argon, etc.), etc.

[0036] In some embodiments, the method for preparing a silicon-based gallium oxide erbium ytterbium doped thin film can use a gallium oxide doped ytterbium target to sputter and prepare a gallium oxide doped ytterbium layer. Further, based on the total number of gallium and ytterbium atoms in the gallium oxide doped ytterbium target being 100%, the atomic concentration of ytterbium in the gallium oxide doped ytterbium target can be 0.1%-2%, for example, 0.2%.

[0037] In some embodiments, the method for preparing the silicon-based gallium oxide erbium ytterbium doped thin film can use a gallium oxide doped erbium target to sputter and prepare a gallium oxide doped erbium layer. Further, based on the total number of gallium and erbium atoms in the gallium oxide doped erbium target being 100%, the atomic concentration of erbium in the gallium oxide doped erbium target can be 0.5%-5%, for example, 2%.

[0038] In some embodiments, in the method for preparing the silicon-based gallium oxide erbium-ytterbium doped thin film, the annealing temperature is preferably above 700° C., and the time is preferably not less than 5 minutes, such as 2 hours.

[0039] [3] The present invention provides a silicon-based gallium oxide erbium ytterbium doped film, comprising a silicon substrate and gallium oxide doped ytterbium layers and gallium oxide doped erbium layers alternately arranged thereon.

[0040] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, the total number of gallium oxide doped ytterbium layers and gallium oxide doped erbium layers may be 2-6 layers, such as 2 layers, 3 layers, 4 layers, 5 layers, 6 layers, preferably 3 layers. 3+ , Yb 3+ The moderate spacing can ensure efficient energy transfer and electron transfer.

[0041] In some preferred examples, the silicon-based gallium oxide erbium ytterbium doped film includes two gallium oxide doped ytterbium layers and a gallium oxide doped erbium layer located between the two gallium oxide doped ytterbium layers. This gallium oxide doped ytterbium / gallium oxide doped erbium / gallium oxide doped ytterbium structure can form a wide band gap / narrow band gap / wide band gap quantum well structure, so that electrons are confined in the light-emitting layer, and the Er 3 + , Yb 3+The interaction between them increases the Er 3+ luminous intensity.

[0042] In the silicon-based gallium oxide erbium ytterbium doped thin film, the thickness of the gallium oxide doped ytterbium layer and the gallium oxide doped erbium layer may be independently no less than 10 nm, and further independently no less than 15 nm.

[0043] In some preferred embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, the ratio of the total thickness of all gallium oxide doped ytterbium layers to the total thickness of all gallium oxide doped erbium layers is 1:0.98-1.02, and more preferably 1:1. At a thickness ratio of 1:1, Er 3+ , Yb 3+ The quantity ratio is balanced, Er 3+ The light itself is strong enough to accept Yb 3+ The energy and electrons transferred.

[0044] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, in the gallium oxide doped ytterbium layer, based on the total number of gallium and ytterbium atoms being 100%, the atomic concentration of ytterbium may be 0.1%-2%, for example, 0.2%.

[0045] In some embodiments, in the silicon-based gallium oxide erbium ytterbium doped film, in the gallium oxide doped erbium layer, based on the total number of gallium and erbium atoms being 100%, the atomic concentration of erbium may be 0.5%-5%, for example, 2%.

[0046] In some embodiments, the silicon-based gallium oxide erbium ytterbium doped film can be obtained by forming alternating gallium oxide doped ytterbium layers and gallium oxide doped erbium layers on a silicon substrate by radio frequency magnetron sputtering and then annealing. The atmosphere of radio frequency magnetron sputtering can be a rare gas (such as argon) atmosphere, etc. The atmosphere of the annealing can be nitrogen, oxygen, a rare gas (such as argon, etc.), etc. The temperature of the annealing is preferably above 700°C, and the time is preferably not less than 5 minutes, such as 2 hours, etc.

[0047] The RF magnetron sputtering can use a gallium oxide doped ytterbium target to prepare a gallium oxide doped ytterbium layer. Further, based on the total number of gallium and ytterbium atoms in the gallium oxide doped ytterbium target being 100%, the atomic concentration of ytterbium in the gallium oxide doped ytterbium target can be 0.1%-2%, for example 0.2%.

[0048] The RF magnetron sputtering can use the gallium oxide doped erbium target to prepare the gallium oxide doped erbium layer. Further, based on the total number of gallium and erbium atoms in the gallium oxide doped erbium target as 100%, the atomic concentration of erbium in the gallium oxide doped erbium target can be 0.5%-5%, for example 2%.

[0049] [4] The present invention provides the use of a silicon-based gallium oxide erbium ytterbium doped thin film prepared by the preparation method described in [2] or a silicon-based gallium oxide erbium ytterbium doped thin film described in [3] in the field of light emitting, especially in electroluminescent devices and electroluminescent lasers.

[0050] The band gap of gallium oxide is ~4.8eV, which can both suppress the temperature quenching of erbium luminescence and ensure moderate conductivity of the device. Gallium oxide has a monoclinic system with lower symmetry, which can effectively increase Er 3+ The 4f transition probability is increased, thus improving the luminescence intensity. In addition, the radius of gallium ions and erbium ions in gallium oxide is close, and erbium doping will not introduce too many defects, ensuring the acquisition of high-quality thin films and devices.

[0051] Er 3+ of 4 I 15 / 2 Ground state and 4 I 13 / 2 The energy difference between the first excited states is ~1540nm, which just corresponds to the minimum loss window of quartz optical fiber. 3+ As a light-emitting center, it is easier to realize silicon-based optoelectronic integration. 3+ middle 4 F 5 / 2 The energy difference between the excited state and the ground state is ~980nm, which is similar to Er 3+ There is a good matching relationship between the energy levels, Yb 3+ , Er 3+ It is more likely to achieve energy transfer and electron transfer between them, which is helpful for Er 3+ In addition, due to the Yb in the gallium oxide doped layer 3+ The concentration is lower, so its band gap is wider. If the erbium-doped gallium oxide of the light-emitting layer is confined between the gallium oxide-doped ytterbium layers on both sides, a wide band gap / narrow band gap / wide band gap quantum well structure can be prepared. This structure can confine electrons in the light-emitting layer, which is similar to Er. 3+ , Yb 3 + The interaction between them jointly improves the luminescence intensity of the device.

[0052] In the present invention, the conductivity type of the silicon layer and the silicon substrate is preferably p-type, and the crystal orientation is preferably <100> .

[0053] The present invention adopts radio frequency magnetron sputtering. The higher the proportion of argon in the sputtering atmosphere, the higher the conductivity of the obtained device. 3+ The lower the pressure during sputtering, the higher the quality of the film obtained. 3+ The stronger the luminescence, the better the pressure of the sputtering chamber during sputtering is. The higher the temperature of the substrate during sputtering, the faster the sputtering rate, and the higher the Er content in the obtained film. 3+However, when the temperature exceeds 300°C, high temperature will induce dislocations, which will reduce the luminescence intensity.

[0054] The thin film obtained by sputtering deposition of the present invention is preferably also subjected to annealing treatment. Specifically, the sample can be placed in a tubular furnace, and an atmosphere such as nitrogen, oxygen or argon is introduced. The deposited thin film is subjected to heat treatment at a temperature above 700° C. for not less than 5 minutes to crystallize gallium oxide and activate rare earth ions. The film is then naturally cooled with the furnace to obtain a thin film.

[0055] The annealing treatment in the present invention is preferably carried out in a nitrogen atmosphere. When the annealing temperature reaches above 700°C, the matrix is ​​crystallized. On this basis, the lower the annealing temperature, the more rare earth Er 3+ The higher the optical activity, the stronger the luminescence. 3+ It can be fully activated. Before this time, the longer the heat treatment, the 3+ The more fully activated it is, the stronger the glow.

[0056] The gallium oxide doped ytterbium layer and the gallium oxide doped erbium layer in the present invention have good uniformity and crystallinity, and the crystal form is β-Ga 2 O 3 .

[0057] The silicon-based gallium oxide erbium ytterbium doped film and the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of realizing population inversion of the present invention are compared with the gallium oxide film and device doped with only erbium. 3+ The luminous intensity is significantly improved, and it is a good silicon-based luminous material and device.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] 1. In the silicon-based gallium oxide erbium ytterbium doped film and the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of realizing population inversion of the present invention, the introduced Yb 3+ Can be with Er 3+ There is an efficient interaction between Yb 3+ The ~980 nm radiation achieved under electric field excitation can be used as a sensitizer to excite Er 3+ Achieve luminescence. 3+ In 4 F 5 / 2 Energy Level and Er 3+ In 4 I 11 / 2 The energy levels are close, Yb 3+ The electrons in the energy level can be transferred to Er 3+ Energy level, making Er 3+ There are more electrons in the excited state energy level to emit light. The interaction between ytterbium and erbium greatly increases Er 3+ luminous intensity.

[0060] 2. In the silicon-based gallium oxide erbium ytterbium doped film and the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of realizing population inversion of the present invention, due to the introduction of Yb 3+ The concentration is low, so the band gap of the gallium oxide doped ytterbium layer is higher than that of the gallium oxide doped erbium layer, and the Fermi level positions of the two are different. Therefore, a band structure similar to a quantum well will be formed in the structure of gallium oxide doped ytterbium / gallium oxide doped erbium / gallium oxide doped ytterbium, which can effectively limit the carriers in the light-emitting layer and further increase Er. 3+ luminous intensity.

[0061] 3. In the silicon-based gallium oxide erbium ytterbium doped thin film and the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of realizing particle number inversion of the present invention, a large number of electrons are excited to above the excited state energy level due to the interaction between erbium ytterbium ions. Under a certain current, the inversion of the number of electrons in the excited state energy level to the number of electrons in the ground state can be realized. 3+ The inversion of the number of particles at the energy level is a necessary condition for realizing the erbium-doped silicon electrolaser. The device prepared by the present invention provides a theoretical and experimental basis for the realization of the erbium-doped silicon electrolaser. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a cross-sectional composition line scanning curve diagram of a three-layer gallium oxide doped ytterbium / doped erbium / doped ytterbium film obtained by using an energy dispersive spectrometer (EDS) in a transmission electron microscope (TEM) in a specific embodiment;

[0063] Figure 2 is the (αhv) obtained by using Tauc's formula for gallium oxide doped with erbium and gallium oxide doped with ytterbium thin films in a specific embodiment. 2 The curve diagram of the relationship between the photon energy hv, the marked area in the figure is the band gap of the two films;

[0064] Figure 3 The valence band spectra of gallium oxide doped with erbium and gallium oxide doped with ytterbium thin films obtained by using X-ray photoelectron spectroscopy (XPS) in a specific embodiment, and the valence band edges of the two thin films are marked in the figure;

[0065] Figure 4 The graph is a near-infrared band electroluminescence spectrum obtained by a gallium oxide doped erbium device and a gallium oxide doped ytterbium / doped erbium / doped ytterbium device under the same voltage in a specific implementation manner;

[0066] Figure 5 is a graph of output optical power density at 1540 nm and input power of a gallium oxide doped erbium device and a gallium oxide doped ytterbium / doped erbium / doped ytterbium device in a specific embodiment;

[0067] Figure 6 is the Er at different currents in the gallium oxide doped ytterbium / erbium / ytterbium doped device in a specific implementation manner3+ The excitation lifetime and decay lifetime change curve of the luminescence peak. The current marked in the figure is the current at which the particle number inversion occurs. DETAILED DESCRIPTION

[0068] The present invention will be further described below in conjunction with the accompanying drawings and specific examples. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. The operating methods in the following examples without specifying specific conditions are usually carried out under conventional conditions or under conditions recommended by the manufacturer.

[0069] In this embodiment, the comparison gallium oxide doped erbium film and device, gallium oxide doped ytterbium film and device and the three-layer gallium oxide doped ytterbium / gallium oxide doped erbium / gallium oxide doped ytterbium film and device related to the present invention are all prepared by radio frequency magnetron sputtering, and the total thickness of the film is similar, and the only difference is the introduction of multiple ytterbium doping layers. The atomic concentration of erbium in the gallium oxide doped erbium target is 2% (based on the total number of gallium and erbium atoms as 100%), and the atomic concentration of ytterbium in the gallium oxide doped ytterbium target is 0.2% (based on the total number of gallium and ytterbium atoms as 100%). The selected substrate is a p-type single crystal silicon wafer with a (100) crystal orientation, single-sided polishing, and a resistivity of ρ<0.01Ω.cm. The heat treatment condition is heat treatment at 700℃ for 2h in a nitrogen atmosphere.

[0070] The specific preparation method is as follows:

[0071] (1) First, perform standard RCA cleaning on the (100) silicon wafer substrate and blow dry the surface with nitrogen. Then, place the silicon wafer into the RF magnetron sputtering chamber, install the target material, and evacuate to a pressure of 2.0×10 -3 Pa, and heat the silicon wafer substrate to 300°C at the same time. After reaching the vacuum degree, pure argon is introduced as the sputtering atmosphere, the flow rate is set to 50sccm, and the sample rotation is turned on. The sputtering power is adjusted to 120W and the sputtering pressure is adjusted to 3.0-4.0Pa to achieve ignition. After the ignition is completed, the sputtering pressure is reduced to 0.5Pa, and pre-sputtering is performed for 5 minutes. During the pre-sputtering, the baffle blocks the silicon wafer substrate.

[0072] (2) Open the shutter and start sputtering. First, sputter the gallium oxide doped ytterbium layer for 6.5 minutes with a thickness of about 30 nm. After the sputtering is completed, turn off the sputtering power supply.

[0073] (3) The gas pressure was readjusted to 3.0-4.0 Pa, and the power of the gallium oxide doped erbium target was adjusted to 120 W for ignition. After ignition, the gas pressure was reduced to 0.5 Pa, and pre-sputtering was performed for 5 minutes. After the pre-sputtering, the shutter was opened for formal sputtering. The sputtering time of the gallium oxide doped erbium layer was controlled to be 16 minutes, so that its thickness was about 60 nm. After the sputtering was completed, the sputtering power was turned off.

[0074] (4) Repeat the operation of (2) to sputter the gallium oxide-doped ytterbium layer again. Control the sputtering time to 6.5 min so that the thickness is about 30 nm. After the sputtering is completed, turn off the power supply and the sputtering instrument.

[0075] (5) Gallium oxide doped erbium thin films were also prepared by radio frequency magnetron sputtering. The same substrate was selected, and the substrate temperature, sputtering pressure, and sputtering atmosphere were all the same. When growing the gallium oxide doped erbium layer, the sputtering time was controlled to 29 minutes, so that its thickness was about 120 nm.

[0076] (6) Gallium oxide doped ytterbium thin film was also prepared by radio frequency magnetron sputtering. The same substrate was selected, and the substrate temperature, sputtering pressure, and sputtering atmosphere were all the same. When growing the gallium oxide doped ytterbium layer, the sputtering time was controlled to be 24 minutes, so that its thickness was about 120 nm.

[0077] (7) The sputtering deposited film needs to be annealed in an ordinary tube furnace. The film is heat treated in a high-purity nitrogen atmosphere, and the temperature is raised to 700°C after 70 minutes, and then kept at 700°C for 2 hours. The whole process is heated and cooled with the furnace.

[0078] (8) The prepared thin film is made into an electroluminescent device. The back side of the silicon substrate is cleaned with a hydrofluoric acid aqueous solution to remove the SiO 2 The Au electrode was deposited on the back of the substrate by sputtering using RF magnetron sputtering. During the sputtering process, pure argon gas was introduced as the sputtering atmosphere with a flow rate of 30 sccm and a sputtering pressure of 3.0 Pa. The power of the Au target was set to 120 W during sputtering, the sputtering time was 5 min, and the thickness of the Au electrode was about 100 nm.

[0079] (9) An ITO transparent electrode was prepared on the surface of the gallium oxide layer by radio frequency magnetron sputtering. During the sputtering process, pure argon gas was introduced as the sputtering atmosphere with a flow rate of 30 sccm, a sputtering pressure of 0.3 Pa, and the substrate temperature was heated to 150°C. During sputtering, the power of the ITO target was set to 60 W, and the sputtering time was 15 min, so that the thickness of the ITO electrode was about 100 nm.

[0080] The obtained three-layer gallium oxide doped with ytterbium / gallium oxide doped with erbium / gallium oxide doped with ytterbium film was subjected to cross-sectional EDS composition test using TEM. The results are as follows Figure 1 As shown, it is confirmed that the prepared film does have an ytterbium / erbium / ytterbium layered structure, and the thickness of the three layers are approximately 30nm, 60nm, and 30nm, respectively.

[0081] In order to confirm that a heterojunction can be formed between gallium oxide doped with erbium and gallium oxide doped with ytterbium, the two films were tested for UV-visible transmission and the band gap was obtained according to the Tauc formula. The results are shown in Figure 2The test results show that the band gaps of the gallium oxide doped erbium layer and the gallium oxide doped ytterbium layer are different, and the band gap of the erbium doped layer is smaller than that of the ytterbium doped layer. Subsequently, the XPS valence band spectrum of the gallium oxide doped erbium and gallium oxide doped ytterbium films was tested, and the valence band edges of the two films were obtained after processing. The results are shown in Figure 3 The test results show that the Fermi level positions in the two films are different, and the contact between the two will form a heterojunction, and the three-layer structure can produce a quantum well structure.

[0082] In order to determine the effect of the introduction of the ytterbium layer on Er 3+ The electroluminescence test was carried out on the gallium oxide doped erbium three-layer thin film device related to the present invention, and the electroluminescence spectra of the two devices under the same voltage were compared. The results are as follows Figure 4 As shown in the spectrum, it can be found that after the ytterbium layer is introduced, Er 3+ The electroluminescence intensity of the two devices was greatly increased. The output optical power density of the two devices was further measured using an optical power meter. The results are as follows: Figure 5 As shown in Figure 2, the maximum optical power density of the three-layer Yb / Er / Yb device can reach 5.0 μW / cm 2 , much higher than the 0.1μW / cm of erbium-doped devices 2 , the introduction of the ytterbium layer increased the luminescence intensity by 49 times.

[0083] In order to determine the addition of ytterbium layer, Er 3+ It is possible to achieve particle number inversion at the energy level. The transient electroluminescence test method is used to measure the Er / Er / Ytterbium devices at different currents. 3+ The excitation lifetime and decay lifetime of the luminescence peak are as follows: Figure 6 The test results show that when the current of the device exceeds 2.0mA, the excitation lifetime begins to be lower than the decay lifetime, that is, at this time, the probability of electrons being excited from the ground state to the excited state is higher than the probability of electrons being de-excited from the excited state back to the ground state. 3+ The number of electrons in the excited state is greater than that in the ground state, which realizes the Er 3+ The number of particles is reversed.

[0084] In summary, the present invention uses radio frequency magnetron sputtering to prepare a silicon-based gallium oxide erbium ytterbium doped device, which is a high-intensity silicon-based light-emitting device; energy transfer and electron transfer occur between the ytterbium ions and the erbium ions in the gallium oxide ytterbium doped layer, so that the number of electrons in the excited state energy level of the erbium ion is greater than that in the ground state, thereby achieving a population inversion; in the three-layer ytterbium / erbium / ytterbium structure device, a heterojunction is formed between the gallium oxide ytterbium doped layer and the erbium doped layer, and the three-layer structure forms a quantum well-type energy band structure.

[0085] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion, characterized in that: It includes a metal electrode, a silicon layer, a light-emitting layer and a transparent conductive electrode arranged in sequence; The light-emitting layer includes gallium oxide doped with ytterbium layers and gallium oxide doped with erbium layers which are arranged alternately.

2. The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion according to claim 1, characterized in that: In the light-emitting layer, the total number of gallium oxide doped ytterbium layers and gallium oxide doped erbium layers is 2-6 layers.

3. The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion according to claim 1, characterized in that: In the light-emitting layer, the thickness of the gallium oxide doped ytterbium layer and the gallium oxide doped erbium layer are independently not less than 10 nm, preferably independently not less than 15 nm.

4. The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion according to claim 1, characterized in that: In the light-emitting layer, the ratio of the total thickness of all gallium oxide doped with ytterbium layers to the total thickness of all gallium oxide doped with erbium layers is 1:0.5-2, preferably 1:

1.

5. The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion according to claim 1, characterized in that: In the gallium oxide doped ytterbium layer, the atomic concentration of ytterbium is 0.1%-2%, based on the total atomic number of gallium and ytterbium being 100%; In the gallium oxide doped erbium layer, the atomic concentration of erbium is 0.5%-5%, based on the total atomic number of gallium and erbium being 100%.

6. The silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion according to claim 1, characterized in that: The turn-on voltage of the silicon-based gallium oxide erbium ytterbium doped electroluminescent device capable of achieving population inversion is less than 10V.

7. A method for preparing a silicon-based gallium oxide erbium-ytterbium doped film using a radio frequency magnetron sputtering system, characterized in that: The preparation method comprises: preparing a gallium oxide doped ytterbium layer and a gallium oxide doped erbium layer by alternate sputtering on a clean heated silicon substrate, and annealing after sputtering to obtain the silicon-based gallium oxide erbium ytterbium doped film.

8. The preparation method according to claim 7, characterized in that: Using a gallium oxide doped ytterbium target to sputter a gallium oxide doped ytterbium layer; taking the total number of gallium and ytterbium atoms in the gallium oxide doped ytterbium target as 100%, the atomic concentration of ytterbium in the gallium oxide doped ytterbium target is 0.1%-2%; Using a gallium oxide doped erbium target to sputter a gallium oxide doped erbium layer; based on the total number of gallium and erbium atoms in the gallium oxide doped erbium target being 100%, the atomic concentration of erbium in the gallium oxide doped erbium target is 0.5%-5%; The annealing temperature is above 700° C. and the annealing time is not less than 5 minutes.

9. A silicon-based gallium oxide erbium ytterbium doped thin film, characterized in that: The invention comprises a silicon substrate and gallium oxide doped ytterbium layers and gallium oxide doped erbium layers arranged alternately thereon.

10. Use of the silicon-based gallium oxide erbium ytterbium doped thin film prepared by the preparation method according to claim 7 or 8 or the silicon-based gallium oxide erbium ytterbium doped thin film according to claim 9 in an electroluminescent device.

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