Electroluminescence sample analysis apparatus

• US 8,934,089 B2
• Filed: 10/25/2012
• Issued: 01/13/2015
• Est. Priority Date: 05/06/2010
• Status: Active Grant

• Current Assignee: Dongguk University Industry-Academic Cooperation Foundation
• Original Assignee: Dongguk University Industry-Academic Cooperation Foundation
• Inventors: Cho, Hoon Young, Lee, Dong Wha, Kwak, Dong Wook, Choi, Hyun Yul
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): RAHMAN, MD M
• Application Number:
  US13/660,765
• Publication Number:
  US 20130057862A1
• Time in Patent Office: 810 Days
• Field of Search: 356/73
• US Class Current: 356/73
• CPC Class Codes: G01N 21/66 electrically excited, e.g. electroluminescence

Abstract

Provided is an apparatus for analyzing an electroluminescence sample, which comprises: a pulse generator for applying a pulse driving signal to the electroluminescence sample; an electroluminescence (EL) detector for receiving electroluminescence which is emitted from the electroluminescence sample according to the application of the pulse driving signal, thereby acquiring a light-receiving signal; a temperature controller for varying the temperature of the electroluminescence sample; and an electroluminescence transient spectroscopy (ELTS) analysis unit for analyzing a change in a time division section of the light-receiving signal delayed depending on a change of the temperature of the electroluminescence sample, and acquiring information on a defect-type charge trap which exists in the electroluminescence sample.

Claims

1. An apparatus for analysis of an electroluminescence sample comprising:

a pulse generator configured for applying a pulse driving signal to the electroluminescence sample;

an electroluminescence (EL) detector configured for acquiring a light-receiving signal by receiving electroluminescence emitted from the electroluminescence sample as a result of application of the pulse driving signal, wherein the light-receiving signal obtained by the EL detector is one of a photo current signal, a photo voltage signal and a capacitance signal;

a temperature controller configured for varying the temperature of the electroluminescence sample; and

an electroluminescence transient spectroscopy (ELTS) analysis unit configured for acquiring information on a defective charge trap existing in the electroluminescence sample by analyzing a change in a transient section of the light-receiving signal according to a temperature change of the electroluminescence sample, wherein the ELTS analysis unit is configured for obtaining at least one of information on an activation energy level of the defective charge trap, a concentration of the defective charge trap and a capture cross-section of the defective charge trap by sampling two time points in the transient section of the light-receiving signal, calculating a difference of the light-receiving signal at the two sampled time points, and using a relation of change in the difference of the light-receiving signal according to the temperature change.

2. The apparatus of claim 1, wherein the pulse generator is configured for generating a square wave pulse in correspondence with temperature change of the electroluminescence sample by the temperature controller, and

wherein the EL detector is configured for detecting EL emitted from the electroluminescence sample in response to the square wave pulse when the square wave pulse is applied.

3. The apparatus of claim 1, wherein the ELTS analysis unit is configured for further obtaining lifetime information by analyzing the transient section of the light-receiving signal obtained at a fixed temperature, and

wherein the lifetime information is at least one of information on a minority carrier and the defective charge trap and can be obtained by calculating a time constant of the transient section that changes exponentially.

4. The apparatus of claim 1, further comprising:

a photographing device configured for obtaining an EL image for EL emitted from the electroluminescence sample; and

a surface defect analysis unit configured for analyzing a surface defect of the electroluminescence sample based on the EL image.

5. The apparatus of claim 4, wherein a microscope is positioned in front of the photographing device on an optical path of the EL, and

wherein the surface defect analysis unit is configured for analyzing the surface defect of the electroluminescence sample based on the EL image in micro units obtained from the photographing device.

6. The apparatus of claim 5, further comprising an optical separator configured for optical separation in such a way that some of the EL emitted from the electroluminescence sample is inputted to the EL detector and the other is inputted to the microscope.

7. The apparatus of claim 1, further comprising a spectroscope configured for detecting a desired wavelength only or cut off an undesired wavelength of EL light emitted from the electroluminescence sample.

8. An apparatus for analysis of an electroluminescence sample comprising:

a pulse generator configured for applying a pulse driving signal to the electroluminescence sample;

an electroluminescence (EL) detector configured for acquiring a light-receiving signal by receiving electroluminescence emitted from the electroluminescence sample as a result of application of the pulse driving signal;

a temperature controller configured for varying the temperature of the electroluminescence sample; and

an electroluminescence transient spectroscopy (ELTS) analysis unit configured for acquiring information on a defective charge trap existing in the electroluminescence sample by analyzing a change in a transient section of the light-receiving signal according to a temperature change of the electroluminescence sample, wherein the ELTS analysis unit is configured for further obtaining lifetime information by analyzing the transient section of the light-receiving signal obtained at a fixed temperature, and wherein the lifetime information is at least one of information on a minority carrier and the defective charge trap and can be obtained by calculating a time constant of the transient section that changes exponentially.

9. The apparatus of claim 8, wherein the pulse generator is configured for generating a square wave pulse in correspondence with temperature change of the electroluminescence sample by the temperature controller, and

wherein the EL detector is configured for detecting EL emitted from the electroluminescence sample in response to the square wave pulse when the square wave pulse is applied.

10. The apparatus of claim 8, further comprising:

a photographing device configured for obtaining an EL image for EL emitted from the electroluminescence sample; and

a surface defect analysis unit configured for analyzing a surface defect of the electroluminescence sample based on the EL image.

11. The apparatus of claim 10, wherein a microscope is positioned in front of the photographing device on an optical path of the EL, and

wherein the surface defect analysis unit is configured for analyzing the surface defect of the electroluminescence sample based on the EL image in micro units obtained from the photographing device.

12. The apparatus of claim 11, further comprising an optical separator configured for optical separation in such a way that some of the EL emitted from the electroluminescence sample is inputted to the EL detector and the other is inputted to the microscope.

13. The apparatus of claim 8, further comprising a spectroscope configured for detecting a desired wavelength only or cut off an undesired wavelength of EL light emitted from the electroluminescence sample.