Spatially and Spectrally Resolved Defects in Polycrystalline CdTe Thin Films Revealed by Quantitative Cathodoluminescence

Conference · Tue Oct 06 04:00:00 EDT 2020

DOI:https://doi.org/10.1109/PVSC40753.2019.9198976· OSTI ID:1726054

Bidaud, Thomas; Moseley, John; Al-Jassim, Mowafak; Amarasinghe, Mahisha; Metzger, Wyatt K.; Collin, Stephane

Increasing the grain size is a potential strategy to reduce grain-boundary recombination and improve performance of thin-film solar cells. Here, CdTe thin films with a range of grain sized were produced by varying the CdC1 2 post-deposition treatment temperature. We use high-resolution cathodoluminescence (CL) microscopy to study recombination and shallow defect levels in detail. Intensities from room temperature CL maps were compared across samples. We find that the CL intensity initially increases with grain size, as expected, but then plateaus as the grain size is increased further. The plateau is correlated with a decrease in the characteristic length-related to the carrier diffusion length-determined from CL intensity profiles near grain boundaries. In addition, low-temperature CL measurements demonstrate the evolution of the defect levels with CdC1 2 temperature.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1726054
• Report Number(s): NREL/CP-5K00-78463; MainId:32380; UUID:e1d726dc-8936-499a-8045-b61d8060159b; MainAdminID:18878
• Country of Publication: United States
• Language: English

Related Subjects

MATERIALS SCIENCE
SOLAR ENERGY
cadmium telluride thin films
cathodoluminescence
nanoscale-materials characterization
polycrystalline materials