Bidirectional optical response device and method of use

Abstract

The present invention provides a bidirectional light response device and a method for using the same. The bidirectional light response device comprises: a substrate, a ferroelectric material layer, a dielectric material layer, a bipolar semiconductor material layer, a first electrode and a second electrode; the ferroelectric material layer is in contact with the substrate; the first part of the dielectric material layer is in contact with the substrate, and the second part of the dielectric material layer covers the ferroelectric material layer; the first region of the bipolar semiconductor material layer is in contact with the first part, and the second region of the bipolar semiconductor material layer is in contact with the second part; the first electrode is in contact with the first region, and the second electrode is in contact with the second region; in the above device, the opposite modulation mechanism of the defect capture region and the ferroelectric modulation region in the bipolar semiconductor material layer is utilized, so that the bidirectional light response device can realize bidirectional switching of the polarity of the bipolar semiconductor material layer only by applying a single gate voltage pulse, so that the bidirectional light response can be realized simply and at a low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a bidirectional light-responsive device and a use method thereof. Background Art

[0002] In the field of modern optoelectronics, semiconductor pn junctions are widely used in the fields of semiconductor electronics and optoelectronics. For example, bidirectional photoresponsive devices can achieve bidirectional photoresponsiveness by bidirectionally switching the polarity of the pn junction so that the photocurrent switches between different directions. Bidirectional photoresponsive devices play an important role in updating the positive and negative conductance weights of optoelectronic neuromorphs, and can reduce the amount of hardware in artificial neural networks.

[0003] In the related art, when bidirectionally switching the polarity of a pn junction, a dual-gate technology, such as dual-gate electrostatic modulation or dual-gate ferroelectric modulation, is usually used to switch the polarity of the pn junction. However, using the dual-gate technology to switch the polarity of the pn junction and thus achieve bidirectional photoresponse is difficult and has high production costs.

[0004] Therefore, how to achieve bidirectional photoresponse simply and at low cost is an urgent problem to be solved. Summary of the invention

[0005] In view of the problems existing in the prior art, the embodiments of the present invention provide a bidirectional light response device and a use method thereof, which can realize bidirectional light response simply and at low cost.

[0006] The present invention provides a bidirectional light-responsive device, comprising: a substrate, a ferroelectric material layer, a dielectric material layer, a bipolar semiconductor material layer, a first electrode and a second electrode;

[0007] The ferroelectric material layer is in contact with the substrate;

[0008] A first portion of the dielectric material layer is in contact with the substrate, and a second portion of the dielectric material layer covers the ferroelectric material layer;

[0009] The first region of the bipolar semiconductor material layer is in contact with the first portion, and the second region of the bipolar semiconductor material layer is in contact with the second portion;

[0010] The first electrode is in contact with the first region, and the second electrode is in contact with the second region;

[0011] Wherein, the first region and the first portion constitute a defect capture region, and the second region and the ferroelectric material layer constitute a ferroelectric modulation region;

[0012] When a single gate voltage pulse is applied to the bidirectional photoresponsive device, the defect capture region is used to generate a first polarity doping in the first region based on the pulse direction of the gate voltage pulse; the ferroelectric modulation region is used to generate a second polarity doping in the second region based on the pulse direction; the first polarity is opposite to the second polarity.

[0013] Optionally, when the pulse direction is a forward gate voltage pulse, the defect capture region is further used to:

[0014] Producing a first polarity doping on the first region, wherein the first polarity is P type;

[0015] The ferroelectric modulation region is further used for:

[0016] Producing a second polarity doping on the second region, wherein the second polarity is N-type;

[0017] The first region of the bipolar semiconductor material layer is a P-type region, and the second region is an N-type region.

[0018] Optionally, when the pulse direction is a negative gate voltage pulse, the defect capture region is further used to:

[0019] Producing a first polarity doping on the first region, wherein the first polarity is N-type;

[0020] The ferroelectric modulation region is further used for:

[0021] Producing a second polarity doping on the second region, wherein the second polarity is P type;

[0022] The first region of the bipolar semiconductor material layer is an N-type region, and the second region is a P-type region.

[0023] Optionally, the bipolar semiconductor material layer is a homojunction.

[0024] Optionally, the material of the substrate is silicon dioxide SiO2, the material of the ferroelectric material layer is copper indium sulfide diphosphide hexasulfide CuInP2S6, the material of the dielectric material layer is hexagonal boron nitride h-BN, and the material of the bipolar semiconductor material layer is tungsten diselenide WSe2.

[0025] Optionally, an ohmic contact is formed between the first electrode, the second electrode and the bipolar semiconductor material layer.

[0026] Optionally, the material of the first electrode and the second electrode is gold Au.

[0027] The present invention also provides a method for using a bidirectional optical response device, comprising:

[0028] applying a single gate voltage pulse to the bidirectional photoresponsive device;

[0029] Among them, the gate voltage pulse is used to drive the defect capture region to produce a first polarity doping in the first region based on the pulse direction of the single gate voltage pulse; and to drive the ferroelectric modulation region to produce a second polarity doping in the second region based on the pulse direction; the first polarity is opposite to the second polarity.

[0030] Optionally, applying a single gate voltage pulse to the bidirectional photoresponsive device comprises:

[0031] applying a single forward gate voltage pulse to the bidirectional photoresponsive device;

[0032] Wherein, the forward gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single forward gate voltage pulse, and the first polarity is P type;

[0033] Driving the ferroelectric modulation region to generate second polarity doping in the second region based on the single forward gate voltage pulse, wherein the second polarity is N-type;

[0034] The first region of the bipolar semiconductor material layer is a P-type region, and the second region is an N-type region.

[0035] Optionally, applying a single gate voltage pulse to the bidirectional photoresponsive device comprises:

[0036] Applying a single negative gate voltage pulse to the bidirectional photoresponsive device;

[0037] The negative gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single negative gate voltage pulse, and the first polarity is N-type;

[0038] Driving the ferroelectric modulation region to generate a second polarity doping on the second region based on the single negative gate voltage pulse, wherein the second polarity is a P type;

[0039] The first region of the bipolar semiconductor material layer is an N-type region, and the second region is a P-type region.

[0040] The present invention provides a bidirectional optical response device and a method for using the same, wherein the bidirectional optical response device comprises: a substrate, a ferroelectric material layer, a dielectric material layer, a bipolar semiconductor material layer, a first electrode and a second electrode; the ferroelectric material layer is in contact with the substrate; the first part of the dielectric material layer is in contact with the substrate, and the second part of the dielectric material layer covers the ferroelectric material layer; the first region of the bipolar semiconductor material layer is in contact with the first part, and the second region of the bipolar semiconductor material layer is in contact with the second part; the first electrode is in contact with the first region, and the second electrode is in contact with the second region; in the above-mentioned bidirectional optical response device, when a single gate voltage pulse is applied to the bidirectional optical response device, the charges in the bipolar semiconductor material layer will pass through the dielectric material layer. It is captured by defects, so that the defect capture region produces a first polarity doping on the first region; at the same time, the ferroelectric modulation region will generate a non-volatile residual polarization field after a single gate voltage pulse, and the residual polarization field produces a second polarity doping on the second region, and the first polarity is opposite to the second polarity; therefore, through the above-mentioned bidirectional optical response device, utilizing the opposite modulation mechanism of the defect capture region and the ferroelectric modulation region in the bipolar semiconductor material layer, the bidirectional optical response device can realize bidirectional switching of the polarity of the bipolar semiconductor material layer only by applying a single gate voltage pulse, that is, the bidirectional optical response device can realize bidirectional switching of the polarity of the semiconductor material layer "with one click", so the bidirectional optical response can be realized simply and at low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 This is one of the structural schematic diagrams of the bidirectional light response device provided by the present invention;

[0043] Figure 2 This is the second structural schematic diagram of the bidirectional light response device provided by the present invention;

[0044] Figure 3 It is a schematic diagram of dark state current-voltage characteristic curves of the bidirectional photoresponsive device provided by the present invention under different gate voltage pulses;

[0045] Figure 4 It is a schematic diagram of the transfer characteristic curve of the bidirectional photoresponsive device provided by the present invention under zero bias voltage and different light intensities;

[0046] Figure 5 It is a schematic flow chart of a method for using the bidirectional optical response device provided by the present invention;

[0047] Figure 6 It is a logical schematic diagram of the bidirectional light-responsive device provided by the present invention switching the polarity of the bipolar semiconductor layer. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] In order to facilitate a clearer understanding of the embodiments of the present application, some relevant knowledge is first introduced as follows.

[0050] Semiconductor pn junctions are the basic building blocks of modern optoelectronics and are widely used in semiconductor electronics, optoelectronics and other fields. However, conventional bulk pn junction-based devices exhibit the characteristics of unidirectional current flow, which limits the tunability of performance and functionality and hinders their application in optoelectronic neuromorphic fields. In addition, bulk semiconductor materials inevitably limit practical applications with low power consumption and high integration. However, due to their ability of electrostatic modulation and strong light-matter interaction, layered two-dimensional materials are considered to be promising materials in electronic and optoelectronic nanodevices such as field-effect transistors, synaptic transistors, sensors and photodetectors.

[0051] Switchable bidirectional response devices based on two-dimensional semiconductor materials play an important role in the update of positive and negative conductance weights in optoelectronic neuromorphic. In related technologies, on the one hand, a dual-gate silicon photodiode array is designed to realize electrostatic doping and reconfigurability of in-sensor image processing. On the other hand, a tungsten diselenide WSe2 homojunction based on a dual-gate structure is designed to realize reconfigurable multifunctional logic and neuromorphic capabilities. On the other hand, a bias voltage-induced sulfur vacancy motion of molybdenum disulfide MoS2 is designed to achieve bidirectional response.

[0052] In the above designs, although great progress has been made in the study of the bidirectional response and physical mechanism of reconfigurable pn devices, it is still very difficult to simply realize non-volatile bidirectional photoresponse.

[0053] In addition, in the related art, dual-gate technology is usually used, and two gates are required to achieve bidirectional light response. That is, under a modulation mechanism, a positive and a negative pulse are used to realize a pn junction, and then a negative and a positive pulse are changed to realize an np junction. The bidirectional light response is achieved by the above polarity switching.

[0054] However, dual-gate technologies, such as dual-gate electrostatic modulation and dual-gate ferroelectric modulation, have some inevitable defects. The production cost of dual-gate electrostatic modulation is high and difficult, and continuous gate voltage consumes extra power; dual-gate ferroelectric modulation also has the problem of high production cost and difficulty.

[0055] To summarize, based on the above-mentioned technical problems, the present invention provides a bidirectional photoresponsive device and a method of use, which can bidirectionally switch the polarity of the np junction by applying only a single gate voltage pulse to the bidirectional photoresponsive device, thereby realizing bidirectional photoresponsiveness simply and at low cost.

[0056] Combine the following Figure 1-Figure 4 The bidirectional photoresponsive device of the present invention is described. Figure 1 This is one of the structural schematic diagrams of the bidirectional optical response device provided by the present invention, see Figure 1 As shown, the bidirectional optical response device includes: a substrate 101, a ferroelectric material layer 102, a dielectric material layer 103, a bipolar semiconductor material layer 104, a first electrode 105 and a second electrode 106;

[0057] The ferroelectric material layer 102 is in contact with the substrate 101;

[0058] The first portion 1031 of the dielectric material layer 103 is in contact with the substrate 101 , and the second portion 1032 of the dielectric material layer 103 covers the ferroelectric material layer 102 ;

[0059] The first region 1041 of the bipolar semiconductor material layer 104 is in contact with the first portion 1031 , and the second region 1042 of the bipolar semiconductor material layer 104 is in contact with the second portion 1032 ;

[0060] The first electrode 105 contacts the first region 1041 , and the second electrode 106 contacts the second region 1042 .

[0061] The first region 1041 and the first portion 1031 constitute a defect capture region, and the second region 1042 and the ferroelectric material layer 102 constitute a ferroelectric modulation region;

[0062] When a single gate voltage pulse is applied to the bidirectional photoresponsive device, the defect capture region is used to generate a first polarity doping on the first region 1041 based on the pulse direction of the gate voltage pulse; the ferroelectric modulation region is used to generate a second polarity doping on the second region 1042 based on the pulse direction; the first polarity is opposite to the second polarity.

[0063] In the embodiment of the present invention, the bipolar semiconductor material layer 104 has good electrical properties and highly adjustable polarity, wherein the polarities of the first region 1041 and the second region 1042 are opposite. For example, if the polarity of the first region 1041 is P-type, the polarity of the second region 1042 is N-type; accordingly, if the polarity of the first region 1041 is N-type, the polarity of the second region 1042 is P-type.

[0064] By the above Figure 1 It can be seen that, due to the large size of the dielectric material layer, the bottom surface of the first portion 1031 is directly in contact with the substrate 101, and the second portion 1032 completely covers the ferroelectric material layer 102. Since the second portion 1032 covers the ferroelectric material layer 102, and the second region 1042 is located above the ferroelectric material layer 102, it can be considered that the first region 1041 overlaps with the first portion 1031, and the second region 1042 overlaps with the ferroelectric material layer 102.

[0065] It should be noted that the ferroelectric material layer 102 is a type of material with ferroelectric effect. It is a branch of pyroelectric materials, has excellent semiconductor properties, clean van der Waals interface and atomic layer thick ferroelectric order. The surface of ferroelectric materials carries electric charge and has memory function. Under the action of an external electric field, the charge can be rearranged, and even if the electric field is no longer in effect, the arranged charge will remain the same. Therefore, this material is widely used in electronic products such as computer memory, high-precision motors, ultra-sensitive sensors and sonar equipment. Ferroelectric materials include barium titanate BaTiO3, potassium dihydrogen phosphate KH2PO4, CuInP2S6, etc.

[0066] The dielectric material in the dielectric material layer 103 is also called dielectric, which is an electrical insulating material. Examples of the dielectric material include nano-barium titanate BaTiO3, nano-titanium dioxide TiO2, h-BN, and the like.

[0067] It should be noted that, in the embodiment of the present invention, there is no restriction on the materials of the ferroelectric material layer 102, the dielectric material layer 103 and the bipolar semiconductor material layer 104. As long as the first region 1041 of the bipolar semiconductor material layer 104 and the first portion 1031 of the dielectric material layer 103 constitute a defect capture region, and the second region 1042 of the bipolar semiconductor material layer 104 and the ferroelectric material layer 102 constitute a ferroelectric modulation region, they all fall within the protection scope of the embodiment of the present invention.

[0068] Optionally, a rule for selecting the first electrode 105 and the second electrode 106 is that an ohmic contact is formed between the first electrode 105 , the second electrode 106 and the bipolar semiconductor material layer 104 .

[0069] In the embodiment of the present invention, the first electrode 105 and the second electrode 106 are a source electrode and a drain electrode, respectively, and the material of the first electrode 105 and the second electrode 106 is Au.

[0070] In the bidirectional light-responsive device provided in an embodiment of the present invention, with respect to the defect capture region, due to the presence of defects between the first portion 1031 and the substrate 101, when a single gate voltage pulse is applied (in the vertical direction), the charges in the channel of the bipolar semiconductor material 104 will pass through the first portion 1031 and be captured by the defects. At this time, the channel polarity changes, and the forward and reverse external electric fields correspond to P-type and N-type doping.

[0071] For the ferroelectric modulation region, since ferroelectric modulation will produce N-type or P-type doping in the channel of the bipolar semiconductor material 104, the ferroelectric material layer 102 will generate a non-volatile residual polarization field after a single gate voltage pulse (vertical direction) pulse operation. The residual polarization field has a doping effect on the channel, and the forward and reverse external electric fields correspond to N-type and P-type doping.

[0072] Therefore, based on the opposite modulation mechanisms of the defect capture region and the ferroelectric modulation region on the channel of the bipolar semiconductor material 104, the bidirectional photoresponsive device can freely switch the polarity of the bipolar semiconductor material 104 from pn junction to np junction by applying a single gate voltage pulse.

[0073] In summary, the bidirectional photoresponsive device provided by the present invention utilizes the opposite modulation mechanisms of the defect capture region and the ferroelectric modulation region in the bipolar semiconductor material layer, so that the bidirectional photoresponsive device can realize bidirectional switching of the polarity of the bipolar semiconductor material layer only by applying a single gate voltage pulse, that is, the bidirectional photoresponsive device can realize bidirectional switching of the polarity of the semiconductor material layer "with one click", so the bidirectional photoresponsive device can realize bidirectional switching of the polarity of the semiconductor material layer simply and at low cost.

[0074] Figure 2 This is the second structural schematic diagram of the bidirectional optical response device provided by the present invention, see Figure 2 As shown, the structure of the bidirectional optical response device can be referred to Figure 1 As shown, in Figure 2 In the embodiment, the first portion 2031 of the dielectric material layer 203 contacts the substrate 201, and the second portion 2032 of the dielectric material layer 203 covers the ferroelectric material layer 202. The first region 2041 of the bipolar semiconductor material layer 204 contacts the first portion 2031, and the second region 2042 of the bipolar semiconductor material layer 204 contacts the second portion 2032.

[0075] The material of the substrate 201 is SiO2, the material of the ferroelectric material layer 202 is CuInP2S6, the material of the dielectric material layer 203 is h-BN, the material of the bipolar semiconductor material layer 204 is WSe2, and the materials of the first electrode 205 and the second electrode 206 are Au.

[0076] Optionally, the bipolar semiconductor material layer 204 is a homojunction.

[0077] In the embodiment of the present invention, based on the two-dimensional WSe2 homojunction, a simple method for switching the polarity of the homojunction is proposed for the first time, that is, a single gate voltage pulse realizes bidirectional polarization switching; wherein h-BN serves as a barrier layer for capturing charges, and CuInP2S6 serves as the local ferroelectric polarization of WSe2. Since the modulation mechanism of the local ferroelectric polarization and charge capture of the two-dimensional WSe2 homojunction is opposite, the bidirectional photoresponsive device can freely switch the polarity of the homojunction from pn junction to np junction in a one-shot manner.

[0078] In the above Figure 1 to Figure 2 In order to switch the polarity of the bipolar semiconductor material, a single gate voltage pulse needs to be applied to the bidirectional photoresponsive device. Figure 2 Taking 2 as an example, the polarity switching of bipolar semiconductor materials is further explained:

[0079] Scenario 1:

[0080] In the case where the pulse direction of the single gate voltage pulse is a forward gate voltage pulse, the defect capture region is further used for:

[0081] Generating a first polarity doping on the first region 2041, wherein the first polarity is P type;

[0082] The ferroelectric modulation region is further used for:

[0083] Producing a second polarity doping on the second region 2042, wherein the second polarity is N-type;

[0084] The first region 2041 of the bipolar semiconductor material layer 204 is a P-type region, and the second region 2042 is an N-type region.

[0085] Specifically, the first region 2041 of the bipolar semiconductor layer 204 overlaps with the first portion 2031 to form a defect capture portion. It should be noted that there is a defect between the first portion 2031 (h-BN) and the substrate 201 (SiO2). When a single gate voltage pulse (vertical direction) is applied, the charge in the channel of the bipolar semiconductor layer 204 (two-dimensional WSe2 homojunction) will pass through the first portion 2031 and be captured by the defect. At this time, the channel polarity changes. If the single gate voltage pulse is a forward pulse at this time, the defect capture region will generate P-type doping in the first region 2041.

[0086] At the same time, the ferroelectric material layer 202 (CuInP2S6) will generate N-type doping on the channel of the bipolar semiconductor layer 204 (two-dimensional WSe2 homojunction) due to ferroelectric modulation, that is, the CuInP2S6 layer will generate a non-volatile residual polarization field after the pulse operation of the gate voltage pulse (vertical direction), and the residual polarization field has a doping effect on the channel. If the single gate voltage pulse is a positive pulse at this time, the electrical modulation area will generate N-type doping on the second area 2042.

[0087] Case 2: When the pulse direction is a negative gate voltage pulse, the defect capture region is further used for:

[0088] Generating a first polarity doping on the first region 2041, wherein the first polarity is N-type;

[0089] The ferroelectric modulation region is further used for:

[0090] Producing a second polarity doping on the second region 2042, wherein the second polarity is P type;

[0091] The first region 2041 of the bipolar semiconductor material layer 204 is an N-type region, and the second region 2042 is a P-type region.

[0092] Specifically, if the single gate voltage pulse is a negative pulse at this time, the defect capture region will generate N-type doping to the first region 2041. At the same time, the electrical modulation region will generate N-type doping to the second region 2042.

[0093] In summary, when a single positive gate voltage pulse is applied, the doping effects of the defect capture region and the ferroelectric modulation region on the WSe2 homojunction channel are P-type and N-type. At this time, the first region of the WSe2 homojunction is P-type, and the second region is N-type, which is a lateral pn junction. When a single negative gate voltage pulse is applied again, the doping effects of the defect capture region and the ferroelectric modulation region on the WSe2 homojunction channel are N-type and P-type. At this time, the first region of the WSe2 homojunction is N-type, and the second region is P-type, which is a lateral np junction.

[0094] Figure 1The polarity switching of the bipolar semiconductor 204 when a single gate voltage pulse is applied is similar to the above Figure 2 The process is similar and will not be described here to avoid repetition.

[0095] In the above bidirectional photoresponsive device, the one-touch polarity switchable homojunction exhibits self-rectifying memory behavior, including up to 10 4 The storage ratio is more than 10 7 The rectification ratio, polarity and magnitude of short-circuit photocurrent and open-circuit voltage can be changed. This work provides a simple method to modify the polarity of 2D homojunctions for optoelectronic neuromorphics.

[0096] Figure 3 Schematic diagram of dark state current-voltage characteristic curve of the bidirectional light-responsive device provided by the present invention under different gate voltage pulses. Figure 3 As shown, Figure 3 It embodies the adjustable bidirectional rectification properties of a one-click polarity-switchable homojunction based on asymmetric van der Waals stacking.

[0097] Specifically, the horizontal axis is the source-drain voltage V d (V), the vertical axis is the source-drain current I d (μA). Gate voltage pulses in different directions show different rectification directions, and as the gate voltage pulse increases, the rectification ratio gradually increases. Under a +80V gate pulse, the rectification ratio reaches 10 4 , and at -80V gate pulse, the rectification ratio is as high as 10 -7 .

[0098] Figure 4 Schematic diagram of the transfer characteristic curve of the bidirectional photoresponsive device provided by the present invention under zero bias and different light intensities. Figure 4 As shown, Figure 4 The bidirectional photovoltaic capability of a one-click polarity-switchable homojunction based on asymmetric van der Waals stacking is demonstrated.

[0099] Specifically, the abscissa is the gate voltage V g (V), the vertical axis is the source-drain current I d (nA). When no bias is applied, the hysteresis window of the transfer curve increases with the increase of light intensity. g =0V, bipolar photocurrents can be observed, reaching 1.10nA and -1.15nA respectively.

[0100] Figure 5 is a schematic diagram of the method for using the bidirectional optical response device provided by the present invention, see Figure 5 As shown, the method of use is as above Figure 1 to Figure 2 The method for using the bidirectional optical response device shown specifically includes step 501:

[0101] Step 501, applying a single gate voltage pulse to the bidirectional photoresponsive device;

[0102] Among them, the gate voltage pulse is used to drive the defect capture region to produce a first polarity doping in the first region based on the pulse direction of the single gate voltage pulse; and to drive the ferroelectric modulation region to produce a second polarity doping in the second region based on the pulse direction; the first polarity is opposite to the second polarity.

[0103] The method for using the bidirectional photoresponsive device provided in an embodiment of the present invention applies a single gate voltage pulse to the bidirectional photoresponsive device, and utilizes the opposite modulation mechanism of the defect capture region and the ferroelectric modulation region in the bipolar semiconductor material layer to realize bidirectional switching of the polarity of the bipolar semiconductor material layer. That is, the bidirectional photoresponsive device can realize bidirectional switching of the polarity of the semiconductor material layer in a "one-click" manner, thereby realizing bidirectional photoresponsiveness simply and at low cost.

[0104] Optionally, the applying a single gate voltage pulse to the bidirectional light-responsive device may specifically include at least one of the following situations:

[0105] Case a: applying a single forward gate voltage pulse to the bidirectional photoresponsive device;

[0106] Wherein, the forward gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single forward gate voltage pulse, and the first polarity is P type;

[0107] Driving the ferroelectric modulation region to generate second polarity doping in the second region based on the single forward gate voltage pulse, wherein the second polarity is N-type;

[0108] The first region of the bipolar semiconductor material layer is a P-type region, and the second region is an N-type region.

[0109] Case b: applying a single negative gate voltage pulse to the bidirectional photoresponsive device;

[0110] The negative gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single negative gate voltage pulse, and the first polarity is N-type;

[0111] Driving the ferroelectric modulation region to generate a second polarity doping on the second region based on the single negative gate voltage pulse, wherein the second polarity is a P type;

[0112] The first region of the bipolar semiconductor material layer is an N-type region, and the second region is a P-type region.

[0113] Figure 6 This is a logic diagram of the bidirectional light-responsive device provided by the present invention switching the polarity of the bipolar semiconductor layer, which specifically includes steps 601-604:

[0114] Step 601: Apply a forward gate voltage pulse to a bidirectional photoresponsive device.

[0115] Step 602: The ferroelectric modulation region in the bidirectional optical response device generates N-type doping on the first region of the bipolar semiconductor layer, and the defect capture portion generates P-type doping on the second region of the bipolar semiconductor layer. At this time, the bipolar semiconductor layer is a pn junction.

[0116] Step 603: Apply a negative gate voltage pulse to the bidirectional photoresponsive device.

[0117] Step 604: the ferroelectric modulation region in the bidirectional optical response device generates P-type doping on the first region of the bipolar semiconductor layer, and the defect capture portion generates N-type doping on the second region of the bipolar semiconductor layer. At this time, the bipolar semiconductor layer is an np junction.

[0118] The preparation method of the bidirectional photoresponsive device is described below:

[0119] Step 1: Silicon wafer pretreatment:

[0120] (1) Use an infrared laser cutting machine to cut a 4-inch silicon wafer into squares with a side length of 1 cm.

[0121] (2) Place the cut silicon wafer on a cleaning rack, pour acetone, isopropyl alcohol and alcohol into it in turn and clean it with an ultrasonic cleaner for 15 minutes to remove organic matter attached to the silicon wafer. Then take it out and blow it dry with a high-purity nitrogen gun.

[0122] Step 2: Material preparation and device construction:

[0123] (1) Mechanical exfoliation method to prepare CuInP2S6, h-BN and WSe2 thin sheets. First, prepare multiple strips of tape, take a block of CuInP2S6 and place it on the sticky side of a piece of tape, and then stick it with the sticky side of another piece of clean tape and tear it off. At this time, some CuInP2S6 sheets will stick to the tape. Repeat the above operation several times to obtain a thinner CuInP2S6, then peel it off onto the PDMS on the slide and observe it under a microscope. According to the color and transparency of the material, find the appropriate layer thickness and size of CuInP2S6 thin sheets. Similarly, h-BN and WSe2 thin sheets can be prepared. The thickness of the h-BN and WSe2 thin sheets is controlled below 15nm, and that of CuInP2S6 is below 50nm.

[0124] It should be noted that material preparation methods include but are not limited to mechanical stripping, chemical vapor deposition, pulsed laser deposition and other methods of preparing materials are all within the scope of protection of the claims of the present invention.

[0125] (2) Build the device through the dry transfer platform, first transfer the CuInP2S6 on the PDMS film to the middle area of ​​the substrate, and then transfer the h-BN and WSe2 sheets on the PDMS film to the target area according to a certain structure. In particular, the h-BN layer covers the CuInP2S6 layer, a part of the WSe2 layer overlaps with the bottom CuInP2S6, and the rest is on the h-BN layer. The specific structure can be referred to Figure 1 as well as Figure 2 .

[0126] It should be noted that transfer methods include but are not limited to dry transfer, wet transfer and other construction methods, all of which are within the scope of protection of the claims of the present invention.

[0127] Step 3: Prepare the drain electrode:

[0128] (1) UV etching technology

[0129] a. Glue coating. Spin AZ-5214 photoresist evenly on the surface of the built device. The glue coating machine is set to three stages: low speed rotation of 500 revolutions per minute (rpm) for 10 seconds (s); then at a speed of 4000 rpm for 20 seconds; and finally at a high speed of 6000 rpm for 20 seconds.

[0130] b. Soft bake: Place the device with the photoresist spun on a heating table preheated at 100°C for 60 seconds.

[0131] c. Exposure. Place the device on the sample stage of the maskless lithography machine, pre-fabricate the characteristic electrode pattern through the drawing software KLayout, adjust the relative position of the sample through the maskless lithography machine, and expose the pre-fabricated pattern.

[0132] d. Development: The exposed device was placed in a developer (model: 2.38% AZ300MIF) and immersed for 40 seconds, then immersed in deionized water for 30 seconds, and finally dried with high-purity nitrogen.

[0133] It should be noted that, in addition to maskless ultraviolet lithography, methods for pre-preparing electrode shapes such as electron beam lithography are all within the scope of protection of the claims of the present invention.

[0134] (2) Thermal evaporation electrode

[0135] The device was placed in a high vacuum coating machine, and the pressure in the evaporation chamber was set to be lower than 4E-10 Pa, the evaporation rate was 0.1Å / s, and the evaporated gold film was 40 nm thick. The evaporated device was then immersed in an acetone solution for 30 seconds, followed by rinsing with deionized water and drying with high-purity nitrogen gas, and the electrode preparation was completed.

[0136] It should be noted that, in addition to the thermal evaporation method, methods for pre-preparing metal electrodes such as electron beam evaporation are all within the scope of protection of the claims of the present invention.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bidirectional photoresponsive device, characterized in that: include: A substrate, a ferroelectric material layer, a dielectric material layer, a bipolar semiconductor material layer, a first electrode and a second electrode; the bipolar semiconductor material layer is a homojunction; The material of the substrate is silicon dioxide SiO2, the material of the ferroelectric material layer is copper indium sulfide diphosphide hexasulfide CuInP2S6, the material of the dielectric material layer is hexagonal boron nitride h-BN, and the material of the bipolar semiconductor material layer is tungsten diselenide WSe2; The ferroelectric material layer is in contact with the substrate; A first portion of the dielectric material layer is in contact with the substrate, and a second portion of the dielectric material layer covers the ferroelectric material layer; The first region of the bipolar semiconductor material layer is in contact with the first portion, and the second region of the bipolar semiconductor material layer is in contact with the second portion; The first electrode is in contact with the first region, and the second electrode is in contact with the second region; Wherein, the first region and the first portion constitute a defect capture region, and the second region and the ferroelectric material layer constitute a ferroelectric modulation region; When a single gate voltage pulse is applied to the bidirectional photoresponsive device, the defect capture region is used to generate a first polarity doping on the first region based on the pulse direction of the gate voltage pulse; the ferroelectric modulation region is used to generate a second polarity doping on the second region based on the pulse direction; the first polarity is opposite to the second polarity; In the case where the pulse direction is a forward gate voltage pulse, the defect capture region is further used for: Producing a first polarity doping on the first region, wherein the first polarity is P type; The ferroelectric modulation region is further used for: Producing a second polarity doping on the second region, wherein the second polarity is N-type; The first region of the bipolar semiconductor material layer is a P-type region, and the second region is an N-type region; In the case where the pulse direction is a negative gate voltage pulse, the defect capture region is further used to: Producing a first polarity doping on the first region, wherein the first polarity is N-type; The ferroelectric modulation region is further used for: Producing a second polarity doping on the second region, wherein the second polarity is P type; The first region of the bipolar semiconductor material layer is an N-type region, and the second region is a P-type region.

2. The bidirectional optical response device according to claim 1, characterized in that: An ohmic contact is formed between the first electrode, the second electrode and the bipolar semiconductor material layer.

3. The bidirectional optical response device according to claim 2, characterized in that: The first electrode and the second electrode are made of gold Au.

4. A method for using a bidirectional optical response device as claimed in any one of claims 1 to 3, characterized in that: include: applying a single gate voltage pulse to the bidirectional photoresponsive device; The gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the pulse direction of the single gate voltage pulse; and to drive the ferroelectric modulation region to generate a second polarity doping on the second region based on the pulse direction; the first polarity is opposite to the second polarity; The applying a single gate voltage pulse to the bidirectional light-responsive device comprises: applying a single forward gate voltage pulse to the bidirectional photoresponsive device; Wherein, the forward gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single forward gate voltage pulse, and the first polarity is P type; Driving the ferroelectric modulation region to generate second polarity doping in the second region based on the single forward gate voltage pulse, wherein the second polarity is N-type; The first region of the bipolar semiconductor material layer is a P-type region, and the second region is an N-type region; The applying a single gate voltage pulse to the bidirectional light-responsive device comprises: Applying a single negative gate voltage pulse to the bidirectional photoresponsive device; The negative gate voltage pulse is used to drive the defect capture region to generate a first polarity doping on the first region based on the single negative gate voltage pulse, and the first polarity is N-type; Driving the ferroelectric modulation region to generate a second polarity doping on the second region based on the single negative gate voltage pulse, wherein the second polarity is a P type; The first region of the bipolar semiconductor material layer is an N-type region, and the second region is a P-type region.

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