Abstract
In a previous paper [1], we reported on Cu(In,Ga)Se2-based (CIGS) solar cell samples collected from different research laboratories and industrial companies with the purpose of understanding the range of CIGS materials that can lead to high-quality and high-efficiency solar panels. Here, we report on electrical measurements of those same samples. Electron-beam induced current and time-resolved photoluminescence (TRPL) gave insights about the collection probability and the lifetime of carriers generated in each absorber. Capacitance and drive-level capacitance profiling revealed nonuniformity in carrier-density profiles. Admittance spectroscopy revealed small activation energies (≤ 0.03 eV) indicative of the inversion strength, larger activation energies (> 0.1 eV) reflective of thermal activation of absorber conductivity and a deeper defect level. Deep-level transient spectroscopy (DLTS) probed deep hole-trapping defects and showed that all samples in this study had a majority-carrier defect with activation energy between 0.3 eV and 0.9 eV. Optical-DLTS revealed deep electron-trapping defects in several of the CIGS samples. This work focused on revealing similarities and differences between high-quality CIGS solar cells made with various structures and fabrication techniques.
Original language | American English |
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Pages (from-to) | 77-83 |
Number of pages | 7 |
Journal | Solar Energy Materials and Solar Cells |
Volume | 174 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Publisher Copyright:© 2017
NREL Publication Number
- NREL/JA-5K00-67143
Keywords
- Admittance spectroscopy
- Cross-sectional electron-beam induced current (EBIC)
- Cu(In,Ga)Se (CIGS)
- Deep-level transient spectroscopy (DLTS)
- Thin-film photovoltaics
- Time-resolved photoluminescence (TRPL)