An amorphous inorganic / organic vertical heterojunction diode and its fabrication method

Abstract

This invention belongs to the field of semiconductor device technology and discloses an amorphous inorganic / organic vertical heterojunction diode and its fabrication method. The diode provided by this invention comprises a substrate, an anode, a cathode, and an organic-inorganic heterojunction. The anode covers a P-type semiconductor layer of the heterojunction, which is composed of a DPPT-TT thin film formed by spin-coating an undoped intrinsic DPPT-TT solution. The cathode covers an N-type semiconductor layer of the heterojunction, which is an a-IGZO thin film grown by magnetron sputtering. Molybdenum is used as the contact material for the anode. The cathode is composed of a glass substrate, a copper sheet, and conductive silver paste. By introducing the amorphous metal oxide semiconductor a-IGZO, the charge transport capability is enhanced. This novel heterojunction structure effectively improves carrier separation and transport efficiency and significantly reduces contact resistance.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor device technology and relates to an amorphous inorganic / organic vertical heterojunction diode and its fabrication method. Background Technology

[0002] As a core component of electronic circuits, diodes directly affect the circuit's efficiency, speed, and stability. While traditional silicon-based diodes offer excellent performance, they are limited in terms of flexibility, large-area fabrication, low-cost manufacturing, and transparent applications. In recent years, organic semiconductors have shown great potential in flexible electronics, wearable devices, transparent displays, and low-cost sensors due to their excellent solution processability, flexibility, large-area fabrication capabilities, and diverse material design options. Organic diodes (such as OLEDs, OPDs, and OFETs) have become a research hotspot. However, the inherent characteristics of organic semiconductor materials also present significant challenges. On the one hand, their carrier mobility is generally low (especially hole mobility), limiting the switching speed and operating frequency of devices. On the other hand, organic materials typically exhibit high bulk resistance, leading to decreased energy transfer efficiency and increased Joule heating. More importantly, achieving ideal ohmic contacts in organic semiconductor devices is difficult. Energy level mismatch and interface defects between electrodes and organic layers often result in huge contact resistance, severely hindering the effective injection and collection of carriers (electrons / holes), becoming a key bottleneck restricting the improvement of device performance (such as turn-on voltage, rectification ratio, and photoresponsivity). Furthermore, the long carrier transport path of traditional planar organic diodes amplifies the negative effects of low mobility and high bulk resistance.

[0003] To overcome the performance limitations of organic semiconductors, a promising strategy is to construct inorganic / organic heterojunctions, combining the high carrier mobility and excellent stability of inorganic materials with the flexibility and ease of fabrication of organic materials. Among these, vertical heterojunctions have attracted widespread attention due to their ability to significantly shorten carrier transport paths, optimize carrier separation and collection efficiency, and facilitate high-density integration. However, integrating traditional crystalline inorganic semiconductors (such as single-crystal silicon and GaAs) with organic materials faces significant challenges: high-temperature fabrication processes are incompatible with organic materials, stringent lattice matching requirements are difficult to meet, and complex interface state problems are difficult to control.

[0004] In summary, the inherent low carrier mobility, high bulk resistance, and persistently high contact resistance of organic semiconductors severely limit the performance ceiling of organic diodes. This makes them unable to match traditional inorganic diodes in terms of switching speed, conduction current, energy efficiency, and long-term stability, thus restricting their application in higher-performance electronic systems. The integration of traditional inorganic semiconductors and organic materials also presents numerous challenges. Overcoming these material and interface physical limitations is key to developing next-generation high-performance organic electronic devices. Summary of the Invention

[0005] To address the aforementioned technical problems, this application combines organic semiconductors and amorphous metal-oxide-semiconductor a-IGZO to construct a novel organic-inorganic heterojunction for diode fabrication. A vertical structure diode based on an organic-inorganic heterojunction composed of a-IGZO and DPPT-TT is proposed. By introducing amorphous metal-oxide-semiconductor a-IGZO, charge transport capability is enhanced. This novel heterojunction structure effectively improves carrier separation and transport efficiency and significantly reduces contact resistance.

[0006] In a first aspect, the present invention provides an amorphous inorganic-organic heterojunction vertical structure diode, comprising:

[0007] The system comprises a substrate, an anode, a cathode, and an organic-inorganic heterojunction. The anode covers a P-type semiconductor layer of the heterojunction, which is composed of a DPPT-TT thin film formed by spin-coating an undoped intrinsic DPPT-TT solution. The cathode covers an N-type semiconductor layer of the heterojunction, which is an a-IGZO thin film grown by magnetron sputtering. The anode uses molybdenum as the contact material. The cathode consists of a glass substrate, a copper sheet, and conductive silver paste. The substrate is a polycrystalline silicon conductive substrate.

[0008] Preferably, the solute in the DPPT-TT solution is DCB, and the concentration of DPPT-TT in the DPPT-TT / DCB solution ranges from 1 to 15 mg / ml.

[0009] Preferably, the raw material for magnetron sputtering growth of a-IGZO thin film is indium gallium zinc oxide (IGZO) target material, wherein In:Ga:Zn=2:2:1 at%, purity above 99.99%; the magnetron sputtering growth conditions are: pressure 8mT, power 100W, rotation speed 10rpm, oxygen ratio 5%, and a 50nm thick a-IGZO thin film is formed at a growth rate of 0.8Å / s. The grown a-IGZO thin film is annealed at 300℃ for 1h as an inorganic semiconductor layer.

[0010] Secondly, the present invention provides a method for fabricating the above-mentioned amorphous inorganic-organic heterojunction vertical structure diode, the method comprising the steps of:

[0011] After ultrasonic cleaning of the polycrystalline silicon conductive substrate, an a-IGZO thin film is grown by magnetron sputtering to form an inorganic semiconductor layer, which is then annealed at 150°C to 300°C for 1 hour. A DPPT-TT / DCB solution is spin-coated onto the surface of the inorganic semiconductor layer to form an organic semiconductor layer, which is then heated at 80°C for 5 minutes and annealed at 150°C for 1 hour. An anode is fabricated on the organic semiconductor layer. Copper sheets are attached to the glass substrate, and conductive silver paste is applied to the bottom of the polycrystalline silicon conductive substrate. The polycrystalline silicon conductive substrate is then attached to the copper sheets on the glass substrate and left for 24 hours to allow the conductive silver paste to solidify and form a cathode.

[0012] In a preferred embodiment of this application, the concentration of DPPT-TT in the DPPT-TT / DCB solution is 5 mg / ml. Accordingly, the spin-coating parameters of the DPPT-TT / DCB solution are set as follows: the initial spin-coating speed is 0 rpm, accelerating to 500 rpm at an acceleration of 200 rpm / s, with the acceleration and constant speed period lasting for 10 s; then accelerating to 1500 rpm at an acceleration of 500 rpm / s, with the acceleration and constant speed period lasting for 60 s; and then decelerating to 0 rpm at an acceleration of 500 rpm / s, with the deceleration and stopping period lasting for 5 s.

[0013] The anode is fabricated by vapor deposition or magnetron sputtering. It should be noted that the anode is fabricated using a metal mask designed according to different circuit structures using layout design software. The fabrication steps for the anode using magnetron sputtering include: growing metallic Mo at a power of 80W and a growth rate of 0.8 Å / s, ultimately forming a metallic Mo anode with a thickness of 80 nm.

[0014] It should be noted that, since vertically structured diodes are not easy to perform pin puncture tests to characterize their electrical properties, copper sheets are attached to the glass substrate, conductive silver paste is applied to the bottom of the polycrystalline silicon conductive substrate, and then the polycrystalline silicon conductive substrate is attached to the copper sheets on the glass to form a cathode to facilitate pin puncture tests.

[0015] Technical Principle: Due to lattice mismatch, a large number of interface states exist between DPPT-TT and a-IGZO. These interface states, like surface states, may contain both partial acceptors and partial donors. To achieve equilibrium, the materials on both sides of the interface release electrons to the acceptors. If the concentration of interface states is high enough, two positively charged depletion layers are generated. The sum of their charges is equal in magnitude and opposite in polarity to the charge of the interface monolayer. They are spatially confined within an extremely thin layer, the "interface," and exist in an exceptionally narrow energy range. This characteristic keeps the Fermi levels on both sides unchanged under an applied voltage. Furthermore, their total trapping cross-section is so large that all electrons crossing the interface are trapped and re-emitted by these states. In the heterojunction diode fabricated in this invention, the effect of high-density interface states on charge transport can be equivalent to a virtual defect layer that introduces a large number of recombination centers at the interface between the two semiconductors. The interface can be equivalent to two back-to-back series-connected Schottky diodes, where the Fermi level pinning effect induced by the interface states leads to the formation of a potential barrier, which severely restricts the directional injection and collection of charge carriers.

[0016] For an independent ideal heterojunction diode, key parameters such as the ideality factor and saturation current can be easily extracted from the output characteristic curve. However, real-world experiments are often the result of the combined effects of various factors. For organic-inorganic heterojunction longitudinal diodes based on DPPT-TT and a-IGZO, their electrical behavior is the result of the coupling effect of multiple complex factors. This device not only has a double Schottky barrier caused by interface states, but also bulk resistance instability caused by the amorphous structure of a-IGZO and poor carrier mobility of the organic layer, which pose a great challenge to the accurate extraction of parameters. Therefore, the differential analysis method was used to study its current-voltage characteristics in depth. This method can effectively decouple the influence of series and parallel resistances, providing more intrinsic information for the analysis of such complex heterojunction structures. This device can be equivalent to an ideal heterojunction diode, a parallel resistor Rsh, and a series resistor Rs. Its current-voltage relationship is shown in Equation (1):

[0017] Formula (1)

[0018] Typically, considering the low leakage current characteristics of the device, the parallel resistance Rsh can be considered infinite. In this case, the junction voltage V... j =VI j R, by differentiating the current I, can be used to derive equation (2):

[0019] Formula (2)

[0020] This method significantly improves the measurement sensitivity of series resistance and allows direct measurement from... The slope of the straight line is used to obtain the value of the series resistance R, thereby effectively eliminating the interference of changes in bulk resistance and contact resistance on parameter extraction, laying the foundation for revealing the intrinsic transport characteristics of heterojunctions.

[0021] The a-IGZO layer region and the cathode have been verified to be in ohmic contact. The a-IGZO layer region and the DPPT-TT region are organic-inorganic heterojunction interfaces. By adjusting the oxygen vacancy concentration of a-IGZO to optimize its carrier characteristics, a significant field-assisted electron emission effect is introduced at the interface to achieve a higher forward conduction current under the same voltage.

[0022] Beneficial Effects: The vertically structured diode provided by this invention combines two materials: organic semiconductor DPPT-TT and amorphous metal-oxide-semiconductor a-IGZO, forming an organic-inorganic heterojunction based on DPPT-TT and a-IGZO. This structure utilizes the excellent film-forming properties and carrier transport capabilities of a-IGZO to construct a diode that achieves low interfacial contact resistance and high charge collection efficiency, enabling rapid separation and transport of carriers at the heterojunction interface. Therefore, the device exhibits high on-state current and excellent rectification characteristics under forward bias. This performance improvement not only significantly enhances the switching efficiency of the device but also paves the way for its integration in advanced electronic applications. For example, in high-sensitivity photodetectors and next-generation display driver circuits, high current density and fast response capabilities can directly improve system performance and speed. Furthermore, another significant advantage of the DPPT-TT and a-IGZO-based organic-inorganic heterojunction lies in its process compatibility and structural tunability. By precisely controlling the composition, deposition conditions, and morphology of the organic layer of a-IGZO, the band structure and interface characteristics of heterojunctions can be "tailored," thereby optimizing the electrical performance and long-term operational stability of devices over a wider range and providing a new material platform for the development of large-area, flexible optoelectronic devices.

[0023] Overall, the organic-inorganic heterojunction vertical diode based on DPPT-TT and a-IGZO effectively modulates the band structure and charge dynamics of the heterojunction through precise interface engineering, significantly improving the carrier injection and separation efficiency, marking an important advancement in the field of organic electronic devices. Attached Figure Description

[0024] Figure 1 This is a structural diagram of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention;

[0025] Figure 2 This is a flowchart of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention;

[0026] Figure 3This is a physical diagram of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention;

[0027] Figure 4 This is a flowchart of the preparation process of the longitudinal SBD based on DPPT-TT in Comparative Example 1 of this invention;

[0028] Figure 5 This is the band structure diagram of the a-IGZO / DPPT-TT heterojunction;

[0029] Figure 6 This is a graph showing the output characteristics of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in Example 1 after annealing at 300 degrees Celsius and testing at room temperature.

[0030] Figure 7 This is a semi-logarithmic graph of the output characteristic curves of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in Example 1 after annealing at 300 degrees and testing at room temperature.

[0031] Figure 8 This is a graph showing the output characteristics of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in Example 2 after annealing at 150 degrees Celsius and testing at room temperature.

[0032] Figure 9 This is a semi-logarithmic graph of the output characteristic curves of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in Example 2 after annealing at 150 degrees Celsius and testing at room temperature.

[0033] Figure 10 This is a device simulation structure diagram of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention;

[0034] Figure 11 This is a simulation output characteristic curve of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT at room temperature in this invention.

[0035] Figure 12 This is a semi-logarithmic coordinate graph of the device simulation output characteristic curve of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention at room temperature;

[0036] Figure 13 This is a simulation diagram of the internal electric field of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT under a 2V bias voltage in this invention.

[0037] Figure 14 The output characteristic curve of the longitudinal SBD based on DPPT-TT in Comparative Example 1 at room temperature is shown.

[0038] Figure 15 The output characteristic curves of the organic-inorganic heterojunction diodes based on a-IGZO and DPPT-TT that have not undergone annealing treatment in Comparative Example 2 are shown at room temperature.

[0039] Figure 16 This is a semi-logarithmic graph of the output characteristic curves of the organic-inorganic heterojunction diodes based on a-IGZO and DPPT-TT that have not undergone annealing treatment in Comparative Example 2 at room temperature. Detailed Implementation

[0040] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but the invention is not limited to these embodiments. The invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention. To provide the public with a thorough understanding of the invention, specific details are described in detail in the following embodiments, but those skilled in the art will fully understand the invention even without these details.

[0041] In the description of this invention, it should be noted that the terms "middle," "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0042] The sources of raw materials and equipment used in the following embodiments and comparative examples are shown below:

[0043] DPPT-TT was purchased from Nanjing Zhiyan Technology Co., Ltd.; dichlorobenzene (DCB) solution was purchased from SigmA-Aldrich; indium gallium zinc oxide (IGZO) sputtering target was purchased from Zhongnuo New Materials Technology Co., Ltd.; polycrystalline silicon substrate (P-type doped, crystal orientation: <100> (Resistivity less than 0.02 Ω·cm) was purchased from Jingying Electronics; conductive silver paste was purchased from Shenzhen Ausbon Co., Ltd.

[0044] Example 1

[0045] Example 1 illustrates the fabrication process of this invention using the fabrication of an organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT as an example; Figure 1As shown, the heterojunction diode involved in the following embodiments includes a substrate 1, an inorganic semiconductor layer 2, an organic semiconductor layer 3, an anode 4, and a cathode. The substrate 1 is a polycrystalline silicon conductive substrate; the inorganic semiconductor layer 2 is an a-IGZO thin film; the organic semiconductor layer 3 is an intrinsic organic material DPPT-TT thin film; the anode 4 is a molybdenum electrode; and the cathode is composed of a glass substrate 7, a copper sheet 6, and conductive silver paste 5.

[0046] Example 1 provides a fabrication process for an organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT, as follows:

[0047] Step S1: A 0.5 mm thick polycrystalline silicon substrate was ultrasonicated in alcohol and deionized water for 5 min each, then dried at 100°C for 10 min on a heating stage. The polycrystalline silicon substrate was then treated in an ultraviolet ozone generator for 30 min; subsequently, it was placed in a magnetron sputtering instrument to grow a 50 nm a-IGZO thin film using an indium gallium zinc oxide (IGZO) target (In:Ga:Zn=2:2:1 at%, purity 99.99%) to form the inorganic semiconductor layer 2. The growth parameters were: pressure 8 mT, power 100 W, rotation speed 10 rpm, oxygen ratio 5%, and a growth rate of 0.8 Å / s to finally form a 50 nm thick a-IGZO thin film. The grown a-IGZO thin film was annealed at 300°C for 1 h.

[0048] Step S2: The polycrystalline silicon substrate with the a-IGZO thin film grown is adsorbed onto a spin coater, and an intrinsic DPPT-TT / DCB mixed solution is dropped onto the surface for spin coating to prepare an organic semiconductor layer 3. The mixed solution here is a DPPT-TT / DCB solution with a concentration of 5 mg / ml. The initial spin coating speed is 0 rpm, which is accelerated to 500 rpm at an acceleration of 200 rpm / s. The acceleration and constant speed time in this stage lasts for 10 s. Then, the acceleration is accelerated to 1500 rpm at an acceleration of 500 rpm / s. The acceleration and constant speed time in this stage lasts for 60 s. After that, the acceleration is decelerated to 0 rpm at an acceleration of 500 rpm / s. The deceleration and stopping time in this stage lasts for 5 s. Then, the substrate is heated at 80 °C for 5 min, and then annealed at 150 °C for 1 h.

[0049] In step S3, the anode mask was ultrasonicated in alcohol and deionized water for 3 minutes each, repeated 3 times. After drying with nitrogen, it was adsorbed onto a spin-coated polycrystalline silicon substrate with an a-IGZO thin film. The anode mask was a stainless steel metal mask with a thickness of 0.1 mm. It was then placed in a magnetron sputtering system and grown at 80 W at a rate of 0.8 Å / s to form an 80 nm thick Mo electrode, which became the anode 4.

[0050] Step S4: Copper sheets are attached to the glass substrate. Then, conductive silver paste is applied to the bottom of the polycrystalline silicon conductive substrate and attached to the copper sheets. The substrate is left to stand for 24 hours to allow the conductive silver paste to solidify, forming a cathode. The cathode includes conductive silver paste 5, copper sheets 6, and glass substrate 7.

[0051] like Figure 1 The diagram shown is a structural diagram of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT in this invention. Figure 2 Is with Figure 1 The corresponding manufacturing process flow chart, such as Figure 3 The image shown is a physical diagram of the device fabricated using the process described in this invention.

[0052] Example 2

[0053] The only difference between Example 2 and Example 1 is that in step S1, the a-IGZO film is annealed at 150°C for 1 hour, while the rest of the operations are the same.

[0054] Comparative Example 1

[0055] Comparative Example 1 provides a typical longitudinal SBD structure, such as Figure 4 As shown, the production process of Comparative Example 1 includes the following four steps:

[0056] In step S1, a 0.5 mm thick glass substrate 8 is ultrasonically treated with alcohol and deionized water for 5 min each, then dried at 100°C for 10 min on a heating stage. A metal mask, made of stainless steel and 0.1 mm thick, is then adsorbed onto the glass substrate. The substrate is placed in a vapor deposition apparatus to deposit 5 nm of metallic Ni and 40 nm of metallic Å. The 5 nm of metallic Ni is deposited at a certain velocity, followed by the 5 nm of metallic Å at a certain velocity, then the 30 nm of metallic Å at a certain velocity, and finally the 5 nm of metallic Å at a certain velocity, thereby forming a metal cathode 9.

[0057] Step S2: The glass substrate treated in step S1 is placed in an ultraviolet ozone generator for 30 minutes; then the glass substrate is adsorbed onto a spin coater, and an intrinsic DPPT-TT / DCB mixed solution is dropped onto the surface for spin coating to prepare an organic semiconductor layer 10. The mixed solution here is a DPPT-TT / DCB solution with a concentration of 5 mg / ml; the initial spin coating speed is 0 rpm, which is accelerated to 500 rpm at an acceleration of 200 rpm / s, and the acceleration and constant speed period lasts for 10 seconds; then it is accelerated to 1500 rpm at an acceleration of 500 rpm / s, and the acceleration and constant speed period lasts for 60 seconds; then it is decelerated to 0 rpm at an acceleration of 500 rpm / s, and the deceleration and stopping period lasts for 5 seconds; then it is heated at 80°C for 5 minutes, and then annealed at 150°C for 1 hour.

[0058] In step S3, the anode mask is ultrasonically treated with alcohol and deionized water for 3 minutes each, repeated 3 times. After drying with nitrogen, it is adsorbed onto the spin-coated glass substrate. The anode mask is made of stainless steel and has a thickness of 0.1 mm. It is then placed in a magnetron sputtering apparatus to grow 80 nm thick Mo. Specifically, the Mo is grown at a power of 80 W and a growth rate of 0.8 Å / s, ultimately forming an 80 nm thick Mo electrode, which becomes anode 11.

[0059] Comparative Example 2

[0060] Comparative Example 2 is based on Example 1 with the annealing process for the magnetron sputtered a-IGZO thin film reduced.

[0061] The organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT prepared in Example 1 was tested on a probe stage, and the output characteristic curve was obtained as follows: Figure 6 and Figure 7 As shown.

[0062] The organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT prepared in Example 2 was tested on a probe stage, and the output characteristic curve was obtained as follows: Figure 8 and Figure 9 As shown.

[0063] The longitudinal SBD with the ordinary structure provided in Comparative Example 1 is placed on the probe stage for testing, and the output characteristic curve is as follows: Figure 14 As shown.

[0064] The unannealed organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT prepared in Comparative Example 2 was tested on a probe stage, and the output characteristic curve was obtained as follows: Figure 15 and Figure 16 As shown.

[0065] The organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT prepared in Example 1 was simulated in the simulation software Silvaco TCAD, and the simulated structure diagram of the device is shown below. Figure 10 As shown, the simulation output characteristic curve of the device is obtained as follows. Figure 11 and Figure 12 As shown, the simulation diagram of the internal electric field of the device under a 2V bias voltage is as follows. Figure 13 As shown in the figure. The simulation results demonstrate the feasibility of Example 1 by showing obvious rectification characteristics. The electric field peak appears at the heterojunction contact interface of a-IGZO / DPPT-TT.

[0066] Figure 5 This is the band structure diagram of the a-IGZO / DPPT-TT heterojunction. A type II heterojunction is expected to form between the a-IGZO and DPPT-TT films, showing a conduction band shift of 0.3 eV (ΔE). C Based on the Fermi level (E) of α-IGZO and DPPT-TT. F The difference was used to calculate the theoretical built-in potential (qV). bi The potential barrier is approximately 0.4 eV. Therefore, electrons on the a-IGZO side only need to overcome a potential barrier of 0.7 eV to be injected into the DPPT-TT side, indicating a low turn-on voltage.

[0067] Will Figure 6 , Figure 7 , Figure 8 and Figure 9 The output characteristic curves and semi-logarithmic coordinate plots of the devices fabricated in the embodiments of the present invention, as represented by the figures, are compared with... Figure 15 and Figure 16 The comparison of the output characteristic curves and semi-logarithmic coordinate plots of the device fabricated in Comparative Example 2 demonstrates the impact of the annealing process on the performance of the organic-inorganic heterojunction diode based on a-IGZO and DPPT-TT proposed in this invention. The on-state current and rectification ratio of the annealed device significantly increase. This is because the unannealed a-IGZO film contains numerous defects, leading to unstable device performance and low mobility. Annealing can activate carrier mobility, improve device speed, repair defects, release stress, and optimize film quality and interfaces.

[0068] Figure 6 and Figure 14 The comparison also intuitively demonstrates that the organic-inorganic heterojunction scheme based on a-IGZO and DPPT-TT proposed in this invention has better device stability performance than the conventional longitudinal SBD structure in the prior art.

[0069] In summary, organic / inorganic vertical heterojunction diodes based on amorphous a-IGZO and DPPT-TT significantly improve the rectification performance and carrier modulation capability of devices due to their excellent interface characteristics and band synergy. This breakthrough demonstrates the broad application potential and research value of these devices in next-generation high-performance, low-power electronic systems. With continuous advancements in material design and fabrication processes, these diodes are expected to play a crucial role in flexible display driving, high-frequency sensor chips, and wearable energy harvesting. For example, in flexible display backplanes, they can serve as high-performance pixel switching elements, achieving faster signal response and lower static power consumption; in biosensors, they can be used to construct high-sensitivity signal detection and conditioning circuits; furthermore, in electronic systems compatible with low-temperature, large-area solution processes, these devices also provide a new technological path for realizing efficient power management modules and RFID tags.

Claims

1. An amorphous inorganic / organic vertical heterojunction diode, characterized in that, The diode comprises: a substrate, an anode, a cathode, and an organic-inorganic heterojunction; the anode covers a region of a P-type semiconductor layer of the heterojunction, which is composed of a DPPT-TT thin film formed by spin-coating an undoped intrinsic DPPT-TT solution; the cathode covers a region of an N-type semiconductor layer of the heterojunction, which is an a-IGZO thin film grown by magnetron sputtering; the anode uses molybdenum as the contact material; the cathode is composed of a glass substrate, a copper sheet, and conductive silver paste; the substrate is a polycrystalline silicon conductive substrate.

2. The amorphous inorganic / organic vertical heterojunction diode as described in claim 1, characterized in that, The magnetron sputtering material for a-IGZO thin films is an indium gallium zinc oxide IGZO target, wherein In: Ga:Zn = 2:2:1 at%, purity above 99.99%; the magnetron sputtering growth conditions are: pressure 8mT, power 100W, rotation speed 10rpm, oxygen ratio 5%, and a 50nm thick a-IGZO thin film is formed at a growth rate of 0.8Å / s. The grown a-IGZO thin film is annealed at 300℃ for 1h as an inorganic semiconductor layer.

3. The amorphous inorganic / organic vertical heterojunction diode as described in claim 1, characterized in that, The solute in the DPPT-TT solution is DCB, and the concentration of DPPT-TT in the DPPT-TT / DCB solution ranges from 1 to 15 mg / ml.

4. The method for fabricating an amorphous inorganic / organic vertical heterojunction diode as described in claim 3, characterized in that, The fabrication method includes the following steps: ultrasonically cleaning the polycrystalline silicon conductive substrate, growing an a-IGZO thin film, annealing it at 300°C for 1 hour, spin-coating a DPPT-TT / DCB solution onto the surface to form an organic semiconductor layer, heating it at 80°C for 5 minutes, and then annealing it at 150°C for 1 hour; attaching copper sheets to a glass substrate, then applying conductive silver paste to the bottom of the polycrystalline silicon conductive substrate and attaching it to the copper sheets to form a cathode; and fabricating an anode on the organic semiconductor layer.

5. The manufacturing method as described in claim 4, characterized in that, The concentration of DPPT-TT in the DPPT-TT / DCB solution is 5 mg / ml.

6. The manufacturing method as described in claim 5, characterized in that, The spin coating parameters for the DPPT-TT / DCB solution were set as follows: the initial spin coating speed was 0 rpm, accelerated to 500 rpm at 200 rpm / s, and the acceleration and constant speed period lasted for 10 s; then accelerated to 1500 rpm at 500 rpm / s, and the acceleration and constant speed period lasted for 60 s; then decelerated to 0 rpm at 500 rpm / s, and the deceleration and stopping period lasted for 5 s.

7. The manufacturing method as described in claim 4, characterized in that, The anode is manufactured by vapor deposition or magnetron sputtering.

8. The manufacturing method as described in claim 7, characterized in that, The anode is fabricated using magnetron sputtering, and the fabrication steps include: growing metallic Mo at a power of 80W and a speed of 0.8Å / s to finally form a metallic Mo anode with a thickness of 80nm.

9. The manufacturing method as described in claim 4, characterized in that, The a-IGZO thin film is grown by magnetron sputtering.

10. The manufacturing method as described in claim 9, characterized in that, The a-IGZO thin film is grown by magnetron sputtering. The fabrication steps include: at a power of 100W, a pressure of 8mT, a rotation speed of 10rpm and an oxygen ratio of 5%, a-IGZO is grown using an indium gallium zinc oxide IGZO target at a speed of 0.8Å / s, and finally a 50nm thick a-IGZO thin film is formed.

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