The role of sodium as a surfactant and suppressor of non-radiative recombination at internal surfaces in Cu2ZnSnS4

Published

Journal Article

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA. It is well-known that sodium improves the performance of Cu2ZnSnS4 (CZTS) devices, yet the mechanism of the enhancement is still not fully understood. This work aims to present a unified account of the relationships between grain boundaries in CZTS, sodium content at these boundaries, non-radiative recombination, and surfactant effects that produce large microstructural changes. Using temperature-dependent photoluminescence measurements, it is demonstrated that samples containing dramatically different grain sizes display identical radiative and non-radiative decay characteristics when sufficient sodium is present in the film. It is also shown that the sodium concentration needed to efficiently passivate non-radiative defects is significantly less that the quantity needed to obtain micrometer-sized CZTS grains. Finally, the high densities of donor-acceptor pairs that are observed in CZTS films appear to reside within the grains themselves, rather than at grain boundaries.

Full Text

Duke Authors

Cited Authors

  • Gershon, T; Shin, B; Bojarczuk, N; Hopstaken, M; Mitzi, DB; Guha, S

Published Date

  • January 1, 2015

Published In

Volume / Issue

  • 5 / 2

Electronic International Standard Serial Number (EISSN)

  • 1614-6840

International Standard Serial Number (ISSN)

  • 1614-6832

Digital Object Identifier (DOI)

  • 10.1002/aenm.201400849

Citation Source

  • Scopus