Identification of critical stacking faults in thin-film CdTe solar cells

S.-H. Yoo, K.T. Butler, A. Soon, A. Abbas, J.M. Walls, A. Walsh

OAI: oai:purehost.bath.ac.uk:publications/0b913362-c24d-4309-ab53-22e690eb85aa • DOI: https://doi.org/10.1063/1.4892844

Cadmium telluride (CdTe) is a p-type semiconductor used in thin-film solar cells. To achieve high light-to-electricity conversion, annealing in the presence of CdCl₂ is essential, but the underlying mechanism is still under debate. Recent evidence suggests that a reduction in the high density of stacking faults in the CdTe grains is a key process that occurs during the chemical treatment. A range of stacking faults, including intrinsic, extrinsic, and twin boundary, are computationally investigated to identify the extended defects that limit performance. The low-energy faults are found to be electrically benign, while a number of higher energy faults, consistent with atomic-resolution micrographs, are predicted to be hole traps with fluctuations in the local electrostatic potential. It is expected that stacking faults will also be important for other thin-film photovoltaic technologies.

/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energy name=SDG 7 - Affordable and Clean Energy