Method for regulating responsivity of quantum dot photodiode detector
By establishing a responsivity model and calibrating it with experimental data, efficient prediction and precise control of the responsivity of quantum dot photodiode detectors were achieved, solving the problems of long design cycles and poor consistency in existing technologies, and improving design efficiency and responsivity consistency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-26
- Publication Date
- 2026-04-14
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing technology, the responsivity optimization method of quantum dot photodiode detectors relies on the empirical design of device structure or single parameter adjustment, which leads to long design cycle, low control efficiency and poor responsivity consistency, and makes it difficult to systematically evaluate the impact of multi-parameter coordinated changes.
A formulaic model relating the responsivity to structural parameters of a quantum dot photodiode detector was established and calibrated using experimental data. Through reverse calculation and optimized design, predictable control of the responsivity was achieved.
It improves device design efficiency and response consistency, reduces the number of experimental trials, is applicable to different material systems and fabrication processes, and has good versatility and automated design capabilities.
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Figure CN121858840A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photodetector technology, and in particular to a method for controlling the responsivity of a quantum dot photodiode detector. Background Technology
[0002] Quantum dot photodetectors have attracted widespread attention in recent years for their tunable band structure, good compatibility in fabrication processes, and excellent photoelectric responsivity in the short-wave infrared and mid-wave infrared bands. In particular, quantum dot photodiode detectors based on PIN structures, which combine low dark current, high responsivity, and good stability, have become a focus of current research and application.
[0003] The responsivity of quantum dot photodiode detectors is typically influenced by a combination of structural parameters and operating conditions, including the thickness distribution of the P-type, intrinsic, and N-type layers, the doping concentration of each functional layer, and factors such as the device's operating temperature and the incident light wavelength. These parameters not only affect light absorption, carrier transport, and recombination processes, but also couple with each other in practical devices, resulting in complex nonlinear relationships in responsivity, dark current, and stability.
[0004] In existing technologies, methods for optimizing the responsivity of quantum dot photodiode detectors mainly rely on empirical design of the device structure or single-parameter tuning, such as changing the absorber layer thickness or doping concentration to improve responsivity. However, these methods typically require numerous repeated experiments to scan parameters, making it difficult to systematically evaluate the combined impact of multiple parameter variations on device responsivity. This results in long device design cycles, low tuning efficiency, and poor responsivity consistency between different batches of devices. Therefore, there is an urgent need to propose a new technical solution that establishes a mathematical model relating the responsivity of a quantum dot photodiode detector to device layer thickness, doping concentration, and operating temperature, and combines this with experimental calibration to achieve efficient prediction and precise control of the quantum dot photodiode detector's responsivity. Summary of the Invention
[0005] The purpose of this invention is to provide a method for controlling the responsivity of a quantum dot photodiode detector. By establishing a formulaic model between responsivity and structural parameters, and calibrating it with experimental data, the structural parameters of the quantum dot photodiode detector can be calculated and optimized under known device operating conditions and target responsivity. This enables predictable control of the device responsivity, thereby improving device design efficiency and responsivity consistency.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a method for controlling the responsivity of a quantum dot photodiode detector. First, a formulaic model is established regarding the responsivity and structural parameters of the quantum dot photodiode detector. The responsivity model is as follows: in, The total loss function of the detector is determined by the following formula: in, These are structural parameters of the responsivity model, which are adjustable variables used to characterize the structural design of quantum dot photodiode detectors. The structural coefficients of the responsivity model are used to characterize the comprehensive influencing factors related to the material system, interface characteristics, and carrier transport behavior of a specific quantum dot photodiode detector.
[0007] in, Indicates the center wavelength of the incident light; For electron charge, =1.6×10 -19 C; Let be Planck's constant. =6.626×10 -34 J·s; The speed of light in a vacuum. =3.0×10 8 ; These represent the thicknesses of the P-type layer, intrinsic layer, and N-type layer, respectively. These represent the doping concentrations of the P-type and N-type layers, respectively; T represents the device operating temperature. , is the overall proportionality coefficient, used to comprehensively characterize the overall impact of non-ideal factors such as optical coupling efficiency, interface loss and carrier collection efficiency on responsivity; The equivalent absorption growth factor for the intrinsic layer thickness; The loss coefficient for intrinsic layer thickness is used to characterize the carrier transport or recombination loss caused by the increase in intrinsic layer thickness. and These are the loss coefficients for the thickness of the P-type and N-type layers, respectively, used to describe the adverse effects of increasing the thickness of the non-primary absorbing layer on the responsivity; and These are the loss intensity coefficients for the doping concentrations of the P-type and N-type layers, respectively. and These are the nonlinear exponents that affect the responsivity, representing the doping concentration of the P-type and N-type layers, respectively. This is the temperature sensitivity coefficient.
[0008] After the response model is established, the following steps are performed: (1) Determine the initial structural parameters of the quantum dot photodiode detector to be controlled, including: P-type layer thickness Intrinsic layer thickness N-type layer thickness P-type layer doping concentration N-type layer doping concentration Simultaneously determine the operating incident light wavelength of the detector. and And set the target responsiveness. ; (2) Perform m responsivity tests on the quantum dot photodiode detector with the initial structural parameters to obtain m sets of measured responsivity. to , where m > 50; (3) The measured response of m groups to Initial structural parameters Incident light wavelength and Substituting the response model of claim 1, the structural coefficients in the model are obtained through fitting calculation, including: Therefore, a responsivity model suitable for this quantum dot photodiode detector is constructed; (4) Based on the aforementioned response model, the target response is... Working incident light wavelength and operating temperature Substituting into the model, under the preset value range and value increment constraints, the structural parameters are... Discretize the values and construct a set of structural parameters formed by combining the discrete values of each structural parameter. Substitute each combination of structural parameters in the set into the response model for calculation, and output the response model result that is closest to the target response. Combination of structural parameters; (5) Based on the combination of output structural parameters, the structure of the quantum dot photodiode detector is designed and optimized or the process is controlled to achieve the target responsivity.
[0009] Furthermore, the thickness of the P-type layer The value ranges from 0 to 200 nm, and the intrinsic layer thickness is... The value range is 0 - 2000 nm, and the N-type layer thickness is... The value range is 0 - 200 nm. When calculating or optimizing the thickness parameter, a continuous value method is not used. Instead, the value is discretized within the above range according to a preset thickness value increment, wherein the thickness value increment is 1–5 nm, so that each thickness parameter forms a finite number of discrete candidate values within its corresponding range.
[0010] Furthermore, the doping concentration of the P-type layer With N-type layer doping concentration The value range is 0 cm⁻ 3 - 1×10 19 cm⁻ 3 When calculating or optimizing the doping concentration parameter, a discretization method is also used. That is, within the specified value range, multiple discrete candidate doping concentration values are generated according to a preset doping concentration increment, where the doping concentration increment is 1 × 10⁻⁶. 15 cm⁻ 3 - 1×10 17 cm⁻ 3 .
[0011] Furthermore, the discretization of the structural parameters refers to, within a pre-defined range of values, adjusting the structural parameters according to a preset increment. Multiple discrete value points are generated, so that each structural parameter corresponds to a finite number of candidate values.
[0012] Furthermore, the aforementioned All are non-negative real numbers. ; The temperature sensitivity coefficient is a real number greater than 0. It changes monotonically with temperature T.
[0013] Furthermore, during the parameter calibration process for establishing the responsivity model, the quantum dot photodiode detector with initial structural parameters is subjected to m responsivity tests, where m > 50. This is because the responsivity model contains 10 structural coefficients, and a sufficient number of experimental samples are needed to constrain the model parameters to ensure the statistical stability and reliability of the model fitting results.
[0014] Furthermore, structural parameters and structural coefficients are not limited to specific values or fixed physical constants, but are determined through experimental testing or numerical simulation based on different material systems, device structures, and fabrication processes.
[0015] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows: By establishing a unified responsivity model, a quantitative correlation between the responsivity of quantum dot photodiode detectors and various structural parameters was achieved, improving the predictability of device design. By solving the structural coefficients in reverse, the number of experimental trials is greatly reduced, and the R&D cost is lowered. This method is applicable to different quantum dot material systems, different device structures and fabrication processes, and has good versatility; The calculation process can be executed automatically by computer hardware and software, and is suitable for device design optimization and real-time response control. Attached Figure Description
[0016] Figure 1 Schematic diagram of a quantum dot photodiode detector Figure 2 This is a flowchart of the method for controlling the responsivity of a quantum dot photodiode detector according to the present invention. Detailed Implementation
[0017] The present invention will be further described in detail below with reference to specific embodiments, so as to provide a more in-depth explanation of the technical features and advantages of the present invention. The specific embodiments of the present invention are merely illustrative and should not be considered as limiting the scope of protection of the present invention in any way.
[0018] The flowchart of the method of the present invention is as follows: Figure 2 As shown, there are many ways to implement this process, and this application only provides two specific embodiments as examples.
[0019] Example 1 This embodiment takes a PIN structure photodiode detector based on HgTe colloidal quantum dots as the research object. The device includes an N-type layer, an intrinsic layer and a P-type layer from bottom to top. The device operates at room temperature and the center wavelength of the incident light is located in the short-wave infrared band.
[0020] (1) In this embodiment, the initial structural parameters of the quantum dot photodiode detector are first determined: the thickness of the P-type layer. = 40 nm, intrinsic layer thickness = 600 nm, N-type layer thickness = 35 nm; P-type layer doping concentration = 5×10 17 cm⁻ 3 N-type layer doping concentration = 1×10 18 cm⁻ 3Operating temperature T0 = 300 K; operating incident light center wavelength λ = 2000 nm; target responsivity R = 0.45 A / W.
[0021] (2) Under the above initial structural parameters, the quantum dot photodiode detector was subjected to m responsivity tests, where m = 100, to obtain 100 sets of measured responsivity data: R1 = 0.252 A / W, R2 = 0.258 A / W, ..., R 100 = 0.268 A / W.
[0022] (3) Substitute the 100 sets of measured responsivity data and the corresponding initial structural parameters into the responsivity model established in this invention, and obtain the structural coefficients corresponding to the device through nonlinear fitting calculation. = 0.30; = 5.0 × 10 4 cm⁻ 1 ; = 5.0 × 10 -4 nm⁻ 1 ; = 2.0 × 10 -3 nm⁻ 1 = 2.0 × 10 -3 nm⁻ 1 ; =2.0 × 10 -19 cm 3 ; = 2.0 × 10 -19 cm 3 ; = 0.6; = 0.6; =0.08, this construct is suitable for the responsivity model of the PIN structure photodiode detector of this HgTe colloidal quantum dot.
[0023] (4) Based on the responsivity model, the target responsivity R = 0.45 A / W, the working incident light wavelength λ = 2000 nm, and the working temperature T = 300 K are substituted into the model to obtain the responsivity. = 5 nm, = 50 nm, = 5nm; = 1×10 15 cm⁻ 3 , = 1×1015 cm⁻ 3 Starting from 1 nm, the thickness increments are 1 nm, and the doping concentration increments are 1 × 10⁻⁶. 16 cm⁻ 3 The incremental values are discretized, and each combination of structural parameters is substituted into the response model for calculation, outputting several sets of results that best approximate the target response. The combination of structural parameters. (5) Taking into account the feasibility of device fabrication process and structural stability, the structural parameters = 45nm, = 500 nm, = 40 nm; = 5.0 × 10 17 cm⁻ 3 , = 5.0 × 10 15 cm⁻ 3 The response is 0.455 A / W, and the closest response to the target response is R = 0.45 A / W.
[0024] Based on the output structural parameters = 45 nm, = 500 nm, = 40 nm; = 5.0 × 10 17 cm⁻ 3 , = 5.0 × 10 15 cm⁻ 3 A PIN structure photodiode detector based on HgTe colloidal quantum dots was designed, with a responsivity close to 0.45 A / W.
[0025] Specifically, this method can achieve efficient prediction and precise control of the responsivity of PIN structure photodiode detectors based on HgTe colloidal quantum dots.
[0026] Specifically, the above calculations and fitting processes are all performed automatically by computer hardware and software; only input is required. = 40nm, = 600 nm, = 35 nm, = 5×10 17 cm⁻ 3 , = 1×10 18 cm⁻ 3T0 = 300 K, λ = 2000 nm, R = 0.45 A / W, and measured responsivity. to That's it, and the final output of the experiment is the structural parameters. = 45 nm, = 500 nm, = 40 nm; = 5.0 × 10 17 cm⁻ 3 , = 5.0 × 10 15 cm⁻ 3 .
[0027] Example 2 This embodiment takes a PI structure photodiode detector based on PbS colloidal quantum dots as the research object. The device includes an intrinsic layer and a P-type layer from bottom to top. The device operates at room temperature and the center wavelength of the incident light is located in the short-wave infrared band.
[0028] (1) In this embodiment, the initial structural parameters of the quantum dot photodiode detector are first determined: the thickness of the P-type layer. = 30 nm, intrinsic layer thickness = 500 nm, N-type layer thickness = 0 nm; P-type layer doping concentration = 8×10 16 cm⁻ 3 N-type layer doping concentration = 0 cm⁻ 3 Operating temperature T0 = 300 K; operating incident light center wavelength λ = 1500 nm; target responsivity R = 0.25 A / W.
[0029] (2) Under the above initial structural parameters, the quantum dot photodiode detector was subjected to m responsivity tests, where m = 200, to obtain 200 sets of measured responsivity data: R1 = 0.182 A / W, R2 = 0.188 A / W, ..., R2 00 = 0.204 A / W.
[0030] (3) Substitute the 200 sets of measured responsivity data and the corresponding initial structural parameters into the responsivity model established in this invention, and obtain the structural coefficients corresponding to the device through nonlinear fitting calculation. = 0.40; = 8.0 × 10 4cm⁻ 1 ; = 4.5 × 10 -4 nm⁻ 1 ; = 3.2 × 10 -3 nm⁻ 1 = 0 nm⁻ 1 ; = 3.5 × 10 -19 cm 3 ; = 0 cm 3 ; = 0.6; = 0; =0.1, this construct is applicable to the responsivity model of the PI structure photodiode detector of this PbS colloidal quantum dot.
[0031] (4) Based on the responsivity model, the target responsivity R = 0.25 A / W, the working incident light wavelength λ = 1500 nm, and the working temperature T = 300 K are substituted into the model to obtain the responsivity. = 5 nm, = 50 nm, = 1×10 15 cm⁻ 3 Starting from 1 nm, the thickness increments are 1 nm, and the doping concentration increments are 1 × 10⁻⁶. 15 cm⁻ 3 The incremental values are discretized, and each combination of structural parameters is substituted into the response model for calculation, outputting several sets of results that best approximate the target response. The combination of structural parameters. (5) Taking into account the feasibility of device fabrication process and structural stability, the structural parameters =50nm, = 300 nm, = 8.5×10 17 cm⁻ 3 The response is 0.258 A / W, and the closest response is R = 0.25 A / W.
[0032] Based on the output structural parameters = 50nm, = 300 nm, = 8.5×10 17 cm⁻ 3A PI structure photodiode detector based on PbS colloidal quantum dots was designed, with a responsivity close to 0.25 A / W.
[0033] Specifically, this method can achieve efficient prediction and precise control of the responsivity of PI structure photodiode detectors based on PbS colloidal quantum dots.
[0034] Specifically, the above calculations and fitting processes are all performed automatically by computer hardware and software; only input is required. = 30nm, = 500 nm, = 0 nm, = 8×10 16 cm⁻ 3 , = 0 cm⁻ 3 T0 = 300 K, λ = 1500 nm, R = 0.25 A / W, and measured responsivity. to That's it, and the final output of the experiment is the structural parameters. =50nm, = 300 nm, = 8.5×10 17 cm⁻ 3 .
[0035] Although specific embodiments of the invention have been shown and described, the invention is not limited to the embodiments described above. It will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the spirit and scope of the invention, and all such changes fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A method for controlling the responsivity of a quantum dot photodiode detector, characterized in that, A formulaic model for the responsivity and structural parameters of quantum dot photodetectors was established, and the responsivity model is as follows: in, The total loss function of the detector is determined by the following formula: in, For the structural parameters of the response model, These are the structural coefficients of the response model.
2. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 1, characterized in that, Indicates the center wavelength of the incident light; For electron charge, =1.6×10 -19 C; Let be Planck's constant. =6.626×10 -34 J·s; The speed of light in a vacuum. =3.0×10 8 ; These represent the thicknesses of the P-type layer, intrinsic layer, and N-type layer, respectively. These represent the doping concentrations of the P-type and N-type layers, respectively; T represents the device operating temperature. , is the overall proportionality coefficient, used to comprehensively characterize the overall impact of non-ideal factors such as optical coupling efficiency, interface loss and carrier collection efficiency on responsivity; The equivalent absorption growth factor for the intrinsic layer thickness; The loss coefficient for intrinsic layer thickness is used to characterize the carrier transport or recombination loss caused by the increase in intrinsic layer thickness. and These are the loss coefficients for the thickness of the P-type and N-type layers, respectively, used to describe the adverse effects of increasing the thickness of the non-primary absorbing layer on the responsivity; and These are the loss intensity coefficients for the doping concentrations of the P-type and N-type layers, respectively. and These are the nonlinear exponents that affect the responsivity, representing the doping concentration of the P-type and N-type layers, respectively. This is the temperature sensitivity coefficient.
3. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 1, characterized in that, After the responsivity model is established, the device responsivity is adjusted through the following steps: (1) Determine the initial structural parameters of the quantum dot photodiode detector to be controlled, including: P-type layer thickness Intrinsic layer thickness N-type layer thickness P-type layer doping concentration N-type layer doping concentration Simultaneously determine the operating incident light wavelength of the detector. and And set the target responsiveness. ; (2) Perform m responsivity tests on the quantum dot photodiode detector with the initial structural parameters to obtain m sets of measured responsivity. to , where m > 50; (3) The measured response of m groups to Initial structural parameters Incident light wavelength and Substituting the response model of claim 1, the structural coefficients in the model are obtained through fitting calculation, including: Therefore, a responsivity model suitable for this quantum dot photodiode detector is constructed; (4) Based on the aforementioned response model, the target response is... Working incident light wavelength and operating temperature Substituting into the model, under the preset value range and value increment constraints, the structural parameters are... Discretize the values and construct a set of structural parameters formed by combining the discrete values of each structural parameter. Substitute each combination of structural parameters in the set into the response model for calculation, and output the response model result that is closest to the target response. Combination of structural parameters; (5) Based on the combination of output structural parameters, the structure of the quantum dot photodiode detector is designed and optimized or the process is controlled to achieve the target responsivity.
4. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 3, characterized in that, The thickness of the P-type layer The value ranges from 0 to 200 nm, and the intrinsic layer thickness is... The value range is 0 - 2000 nm, and the N-type layer thickness is... The value range is 0-200 nm, and the thickness increment is 1-5 nm; the doping concentration of the P-type layer... With N-type layer doping concentration The value range is 0cm⁻ 3 - 1×10 19 cm⁻ 3 The doping concentration increment is 1×10 15 cm⁻ 3 - 1×10 17 cm⁻ 3 .
5. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 3, characterized in that, Discretizing the structural parameters refers to setting the structural parameters within a pre-defined range of values according to a preset increment. Multiple discrete value points are generated, so that each structural parameter corresponds to a finite number of candidate values.
6. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 3, characterized in that, The All are non-negative real numbers. ; The temperature sensitivity coefficient is a real number greater than 0. It changes monotonically with temperature T.
7. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 3, characterized in that, This method enables efficient prediction and precise control of the responsivity of quantum dot photodiode detectors.
8. The method for controlling the responsivity of a quantum dot photodiode detector as described in claim 3, characterized in that, The calculation process of this method can be automatically executed by computer hardware and software. Only the thickness of each layer, doping concentration, incident wavelength and operating temperature need to be input to output the responsivity. It is suitable for design optimization and real-time control of photodetector responsivity.