2023/10/10 by Alan Robert Bowman, Jacob J Leaver, Bowman, Alan R +9
Engineering · Materials Science · #Advanced Semiconductor Detectors and Materials #Applied Physics (physics.app-ph) #Chalcogenide Semiconductor Thin Films #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Optics (physics.optics) #Quantum Dots Synthesis And Properties
paper · pdf · doi:10.48550/arxiv.2310.06496
openalex publication_date 2023/10/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
CdTe is the most commercially successful thin-film photovoltaic technology to date. The recent development of Se-alloyed CdSexTe1-x layers in CdTe solar cells has led to higher device efficiencies, due to a lowered bandgap improving the photocurrent, improved voltage characteristics and longer carrier lifetimes. Evidence from cross-sectional electron microscopy is widely believed to indicate that Se passivates defects in CdSexTe1-x solar cells, and that this is the reason for better lifetimes and voltages in these devices. Here, we utilise spatially resolved photoluminescence measurements of CdSexTe1-x thin films on glass to study the effects of Se on carrier recombination in the material, isolated from the impact of conductive interfaces and without the need to prepare cross-sections through the samples. We find further evidence to support Se passivation of grain boundaries, but also identify an associated increase in below-bandgap photoluminescence that indicates the presence of Se-enhanced luminescent defects. Our results show that Se treatment, in tandem with Cl passivation, does increase radiative efficiencies. However, the simultaneous enhancement of defects within the grain interiors suggests that although it is overall beneficial, Se incorporation may still ultimately limit the maximum attainable efficiency of CdSexTe1-x solar cells.