Performance evaluation of multi-junction solar cells by spatially resolved electroluminescence microscopy
Lijing Kong1, Zhiming Wu1, Shanshan Chen1
1Department of Physics, Fujian Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005 People's Republic of China.
Nanoscale Research Letters
|April 9, 2015
Summary
This study introduces a new electroluminescence microscopy system for analyzing multi-junction solar cells. The technology effectively identifies defects and correlates electroluminescence intensity with performance, aiding in solar cell evaluation.
Area of Science:
- Photovoltaics
- Materials Science
- Optical Engineering
Background:
- Multi-junction solar cells are crucial for high-efficiency solar energy conversion.
- Characterizing defects and performance is essential for optimizing solar cell technology.
- Existing methods may lack the resolution or comprehensive analysis needed for complex solar cell structures.
Purpose of the Study:
- To develop and validate an electroluminescence microscopy and spectroscopy system for analyzing multi-junction solar cells.
- To investigate the correlation between visual defect identification and external quantum efficiency (EQE) in solar cells.
- To establish a method for evaluating the current matching status of multi-junction solar cells.
Main Methods:
- Development of a combined electroluminescence microscopy and spectroscopy system.
- Characterization of triple-junction solar cells with varying efficiencies.
- Analysis of mechanical damages and material defects using high-resolution imaging.
- Correlation of electroluminescence intensity with short-circuit current density (JSC).
Main Results:
- The system clearly distinguished mechanical damages and material defects in solar cells with high resolution.
- External quantum efficiency (EQE) measurements showed that electric leakage significantly degraded cell performance.
- Electroluminescence intensity (gray value) was found to be nearly proportional to the short-circuit current density (JSC).
Conclusions:
- The developed electroluminescence system offers a powerful tool for visually analyzing multi-junction solar cells.
- This technology can effectively identify defects and assess their impact on solar cell performance.
- The findings suggest a potential method for evaluating the current matching status of multi-junction solar cells, crucial for optimizing energy output.
