Carrier-resolved photo-hall system and method

Patent metadata

Field	Value
Publication number	US-11041827-B2
Application number	US-201916382937-A
Country	US
Kind code	B2
Filing date	Apr 12, 2019
Priority date	Apr 12, 2019
Publication date	Jun 22, 2021
Grant date	Jun 22, 2021

Abstract

Systems and methods are provided that facilitate high-sensitivity, carrier-resolved photo-Hall effect measurements. Majority and minority carrier properties can be measured and determined simultaneously. In one aspect, a system and method determine majority carrier type, density and mobility and, with modulated illumination, minority carrier mobility and photocarrier density. In another aspect, a system and method can determine hole and electron mobility, photocarrier density, absorbed photon density, recombination lifetime and diffusion length for hole, electron and ambipolar transport.

First claim

What is claimed is:

1. A measurement system, comprising:
a measurement chamber;
an optics module coupled to the measurement chamber and comprising:
a light source; and
a filter that modulates light from the light source and illuminates a sample under test with modulated light from the light source, wherein the filter is a harmonic modulator filter placed along a light path between the light source and the sample under test that produces single harmonic oscillation under constant rotation; and

a Hall measurement module that outputs one or more Hall measurements that indicate a first carrier mobility, a second carrier mobility and photocarrier density of the sample under test based on the modulated light.

2. The measurement system of claim 1 further comprising:
an instruments module coupled to the Hall measurement module and provides an output that indicate the first carrier mobility, the second carrier mobility and photocarrier density.

3. The measurement system of claim 2 , wherein the instruments module comprises a deep neural network that determines a quality of the Hall measurements from the Hall measurement module.

4. The measurement system of claim 2 , wherein the instruments module determines conductivity and Hall coefficient as a function of an intensity of the modulated light based on the Hall measurements from the Hall measurement module.

5. The measurement system of claim 2 , wherein the instruments module determines conductivity and Hall coefficient as a function of an oscillation of the modulated light based on the Hall measurements from the Hall measurement module.

6. The system of claim 1 , wherein the Hall measurement module calculates a hole mobility, an electron mobility, a photocarrier density, a recombination lifetime, a diffusion length for hole, electron and ambipolar transport at various discrete light intensities.

7. A method comprising:
illuminating, by a system operatively coupled to a processor, a sample under test provided in a measurement chamber;
modulating, by the system, the illumination of the sample under test, wherein the modulating the illumination of the sample under test comprises oscillating a light intensity of the illumination around a selected light intensity;
measuring, by the system, Hall measurements of the sample under test based on the modulated illumination of the sample under test; and
determining, by the system, a first carrier mobility, a second carrier mobility and the photocarrier density in the sample under test based on the Hall measurements and the modulated illumination.

8. The method of claim 7 , wherein the modulating the illumination of the sample under test further comprises modulating an intensity of the illumination from a first intensity to a second intensity.

9. The method of claim 8 , wherein the measuring Hall measurements comprises measuring conductivity and Hall coefficient of the sample under test as a function of the intensity of the illumination.

10. The method of claim 7 , wherein the measuring Hall measurements comprises measuring conductivity and Hall coefficient of the sample under test as a function of the oscillation of the light intensity.

11. The method of claim 7 , wherein the determining the first carrier mobility, the second carrier mobility and the photocarrier density further comprises:
classifying, by a deep neural network, a quality of the Hall measurements; and
calculating the first carrier mobility, the second carrier mobility and the photocarrier density based on the certain measure of quality of the Hall measurements.

12. The method of claim 7 , wherein the determining the first carrier mobility, the second carrier mobility and photocarrier density further comprises:
calculating a slope for a change in a Hall coefficient over a change in conductivity from the Hall measurements; and
calculating the first carrier mobility, the second carrier mobility and the photocarrier density based on the slope for the change in the Hall coefficient over the change in the conductivity.

13. The method of claim 7 , further comprising determining, by the system, a number discrete light intensity settings to illuminate the sample under test and calculate a hole mobility, an electron mobility, a photocarrier density, a recombination lifetime, a diffusion length for hole, electron and ambipolar transport at each discrete light intensity setting.

14. A computer program product that facilitates Hall measurements, the computer program product comprising a non-transitory computer readable medium having program instructions embodied therewith, the program instructions are executable by a processor to cause the processor to:
illuminate a sample under test provided in a measurement chamber;
modulate the illumination of the sample under test, wherein the modulation comprises oscillate a light intensity of the illumination around a selected light intensity;
measure Hall measurements of the sample under test based on the modulated illumination of the sample under test; and
determine a first carrier mobility, a second carrier mobility and photocarrier density in the sample under test based on the Hall measurements and the modulated illumination.

15. The computer program product of claim 14 , wherein the program instructions are further executable by the processor to cause the processor to modulate an intensity of the illumination from a first intensity to a second intensity.

16. The computer program product of claim 15 , wherein the program instructions are further executable by the processor to cause the processor to measure a conductivity and a Hall coefficient of the sample under test as a function of the intensity of the illumination.

17. The computer program product of claim 14 , wherein the program instructions are further executable by the processor to cause the processor to measure a conductivity and a Hall coefficient of the sample under test as a function of the oscillation of the light intensity.

18. The computer program product of claim 14 , wherein the program instructions are further executable by the processor to cause the processor to determine a number discrete light intensity settings to illuminate the sample under test and calculate a hole mobility, an electron mobility, a photocarrier density, a recombination lifetime, a diffusion length for hole, electron and ambipolar transport at each discrete light intensity setting.

19. The computer program product of claim 14 , wherein the determination of the first carrier mobility, the second carrier mobility and the photocarrier density comprises:
classify, by a deep neural network, a quality of the Hall measurements; and
calculate the first carrier mobility, the second carrier mobility and the photocarrier density based on the certain measure of quality of the Hall measurements.

20. The computer program product of claim 14 , wherein the determination the first carrier mobility, the second carrier mobility and photocarrier density further comprises:
calculate a slope for a change in a Hall coefficient over a change in conductivity from the Hall measurements; and
calculating the first carrier mobility, the second carrier mobility and the photocarrier density based on the slope of change in a Hall coefficient over a change in conductivity.

Assignees

• IBM

Inventors

• Gunawan Oki
• Zhou Wang

Classifications

• G01R33/1253 Primary

  Measuring galvano-magnetic properties · CPC title

• G01N27/72 Primary

  by investigating magnetic variables · CPC title

• G01R33/07

  Hall effect devices · CPC title

• G01R33/032

  using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} · CPC title