Search

CN-122029411-A - Method for evaluating degradation of photodetector

CN122029411ACN 122029411 ACN122029411 ACN 122029411ACN-122029411-A

Abstract

A method for evaluating degradation of a photo detector (112), the photo detector (112) comprising at least one photosensitive element (116), the photo detector (112) being configured for generating at least one detector current from an illumination of the photosensitive element (116) by light, the photo detector (112) further comprising at least one evaluation unit (120) for evaluating the detector current, wherein the method comprises a) determining at least one detector current, b) evaluating the detector current with respect to at least one reference value to obtain at least one relative detector current value, and c) deriving at least one degradation information item with respect to the photosensitive element (116) using the relative detector current value, the degradation information item describing performance degradation due to temperature hysteresis behavior, aging, excessive temperature and/or excessive illumination.

Inventors

  • M. st Ge
  • T-J. Osterman
  • C.M. Augustine

Assignees

  • 特里纳米克斯股份有限公司

Dates

Publication Date
20260512
Application Date
20241015
Priority Date
20231016

Claims (15)

  1. 1. A method for evaluating degradation of a photo detector (112), the photo detector (112) comprising at least one light sensitive element (116), the photo detector (112) being configured for generating at least one detector current depending on an illumination of the light sensitive element (116) by light, the photo detector (112) further comprising at least one evaluation unit (120) for evaluating the detector current, wherein the method comprises: a) Determining at least one detector current; b) Evaluating the detector current with respect to at least one reference value to obtain at least one relative detector current value, and C) At least one degradation information item about the photosensitive element (116) is derived using the relative detector current value, the degradation information item describing performance degradation due to temperature hysteresis behavior, aging, excessive temperature and/or excessive irradiation.
  2. 2. Method according to the preceding claim, wherein the detector current comprises a detector dark current, wherein the reference value comprises at least one calibration value, wherein the relative detector current value comprises at least one degradation quotient obtained using the detector dark current.
  3. 3. The method according to any of the preceding claims, wherein the photo detector (112) further comprises at least one reference resistor (122), the photo detector (112) being configured for generating at least one reference current through the reference resistor (122), wherein the evaluation unit (120) is configured for evaluating the reference current, wherein step a) comprises determining a detector dark current and the reference current through the reference resistor (122), wherein in step b) the reference current is used as the reference value.
  4. 4. Method according to the preceding claim, wherein the relative detector current value comprises at least one degradation quotient obtained using the detector dark current and the reference current.
  5. 5. The method according to either one of the preceding two claims, wherein step a) further comprises determining at least one temperature-corrected detector impedance of the photosensitive element (116) from the detector current, wherein step a) further comprises determining at least one temperature-corrected reference impedance of the reference resistor (122) from the reference current, wherein in step b) the temperature-corrected reference impedance is used as the reference value, wherein the temperature-corrected detector impedance is evaluated with respect to the temperature-corrected reference impedance, wherein the relative detector current value comprises at least one degradation quotient obtained using the temperature-corrected detector impedance and the temperature-corrected reference impedance.
  6. 6. The method according to any of the preceding claims, wherein the photo detector (112) is comprised by at least one spectrometer device (110), the spectrometer device (110) comprising at least one light source (124) for generating illumination light (126) illuminating an object (114) applied to at least one object interface (152) of the spectrometer device (110), the spectrometer device (110) further comprising at least one first light path (154) configured for allowing the illumination light (126) to propagate to the photo detector (112) by passing the object interface (152) at least once, the spectrometer device (110) further comprising at least one second light path (156) configured for allowing the illumination light (126) to propagate to the photo detector (112) without passing the object interface (152), wherein the method comprises determining at least one detector current and at least one detector current in step a) via the second light path (156), wherein the illumination current and the detector current in step b) comprises evaluating the illumination current with respect to the detector current in step b).
  7. 7. The method according to any of claims 2, 4, 5 or 6, wherein the degradation information item indicates a degraded photosensitive element (116) if the degradation quotient differs from a predetermined value by more than a given threshold value.
  8. 8. The method according to the preceding claim, the photodetector (112) comprising a plurality of photosensitive elements (116), wherein the method is performed for each photosensitive element (116), wherein deriving the degradation information item about the photosensitive element (116) comprises comparing degradation quotient of the plurality of photosensitive elements (116), wherein the degradation information item indicates a degraded photosensitive element (116) if a difference of the degradation quotient of the photosensitive element (116) and at least one of the plurality of photosensitive elements (116) exceeds a given threshold, wherein the comparison degradation quotient of the plurality of photosensitive elements (116) comprises at least one of an average value of degradation quotient of the plurality of photosensitive elements (116), a minimum degradation quotient of the plurality of photosensitive elements (116), a maximum degradation quotient of the plurality of photosensitive elements (116).
  9. 9. The method according to any of the preceding claims, wherein if the degradation information item indicates a degraded photosensitive element (116), the method further comprises preventing erroneous measurements performed with the degraded photosensitive element (116) from being displayed.
  10. 10. The method according to any of the preceding claims, wherein if the degradation information item indicates a degraded photosensitive element (116) within a predetermined period of time, the method comprises identifying a defective photosensitive element (116).
  11. 11. The method according to any of the preceding claims, wherein the degradation information item comprises at least one information item selected from the group consisting of at least one ageing information item, at least one hysteresis information item, at least one over-temperature information item, at least one over-irradiation information item.
  12. 12. A photo detector (112) comprising at least one light sensitive element (116), the photo detector (112) being configured for generating at least one detector current from an illumination of the light sensitive element (116) by light, wherein the photo detector (112) further comprises at least one evaluation unit (120) for evaluating the detector current, wherein the photo detector (112) is configured for performing the method according to any of the preceding claims.
  13. 13. A spectrometer device (110) for obtaining spectroscopic information about at least one object (114), the spectrometer device (110) comprising at least one photodetector (112) according to the preceding claim.
  14. 14. A computer program comprising instructions which, when the program is executed by a photodetector (112) according to any one of the preceding claims referring to a photodetector (112), cause the photodetector (112) to perform the method according to any one of the preceding claims referring to a method.
  15. 15. A computer readable storage medium comprising instructions which, when executed by a photodetector (112) according to any one of the preceding claims directed to a photodetector (112), cause the photodetector (112) to perform the method according to any one of the preceding claims directed to a method.

Description

Method for evaluating degradation of photodetector Technical Field The present invention relates to a method for evaluating degradation of a photodetector, a photodetector and a spectrometer device comprising the photodetector. The invention further relates to a computer program and a computer readable storage medium for performing the method. Such devices and methods may be used for research or monitoring purposes in general, in particular in the Infrared (IR) spectral region, in particular in the Near Infrared (NIR) spectral region, and in the Visible (VIS) spectral region, for example in a spectral region that allows simulating human color vision capabilities. However, additional applications are also possible. Background Spectrometer devices are known to be efficient tools for obtaining information about the spectral characteristics of an object when emitting, irradiating, reflecting and/or absorbing light. Thus, the spectrometer device may help analyze the sample or other tasks interested in information about the spectral characteristics of the object. Typically, in a spectrometer device, the spectral information is obtained via one or more detectors and one or more wavelength selective optical elements, such as one or more dispersive optical elements, filters (e.g., bandpass filters), prisms, gratings, interferometers, etc. The spectrometer device may further comprise one or more light sources. Thus, in spectroscopy, tunable light sources (e.g., lasers) and/or broadband emission light sources (e.g., halogen gas filled bulbs and/or hot filaments) are typically used. However, in addition or alternatively, other light sources, such as light emitting diodes, are also proposed for the visible spectral region. The detector of the spectrometer device may comprise any type of photosensitive element, such as one or more single-or multi-pixel detectors, a line detector, or an array detector having a one-or two-dimensional array of pixels. These detectors may generate charge carriers as a result of illumination by light, which is known as the photo-effect, and thus typically represent photo-detectors. In general, a photodetector (such as a photodiode and/or a photoresistor) may be configured to detect an optical signal via a change in detector current. The performance of a photodetector may generally vary with its temperature. In particular, the detector signal of an infrared photodetector may be affected by a temperature rise due to thermally activated charge carriers and/or traps that may be generated in the photosensitive material of the photodetector. Thermally activated charge carriers and/or traps may have a fairly long lifetime and therefore the photo detector may exhibit a temperature hysteresis, i.e. the photo detector may exhibit thermally induced performance degradation for a period of time after returning to a lower temperature. Further, photodetectors, particularly photodetectors based on semiconductor devices, may exhibit aging, i.e., degradation in performance over time. Further, too high a temperature and/or excessive irradiation of the photodetector may also cause degradation of the performance of the photodetector. Performance degradation due to temperature hysteresis, aging, excessive temperatures, and/or excessive irradiation may render the photodetector unusable and/or alter the characteristics of the photodetector such that the photodetector may generate erroneous measurements without recalibration. This is particularly critical for spectroscopic systems that use multiple photodetectors that may experience different aging and/or hysteresis. KR 2019 0107123 A1 discloses a method of monitoring time-varying fluorescence emitted from a fluorescent agent within a diffusely reflective medium having time-varying optical properties, the method comprising the step of providing a measurement dataset comprising a plurality of measurement entries. Each measurement data entry includes at least two measurements taken from the patient at one data acquisition time before and after administration of the fluorescent agent. The step includes detecting by a filtered photodetector a Flr meas signal adjacent to the diffusely reflective medium, a DR em signal, and a DR em, Filtered signal during illumination of the diffusely reflective medium with light of an excitation wavelength and at least one DR signal selected from the group consisting of. The method further includes the steps of identifying a post-balance portion of the measurement dataset and converting each Flr meas signal of each measurement data entry in the post-balance portion of the measurement dataset to an IF Fluorescent agent signal that is representative of the detected fluorescence intensity emitted only by the fluorescent agent within the diffuse reflective medium. The method includes the step of removing the effects of excitation light leakage and the effects of autofluorescence from the Flr meas signal. US 2013/015331 A1 describes an appa