In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 8, No. 1 ( 2018-01-30)
Abstract:
Kelvin Probe Force Microscopy, Photoluminescence imaging and numerical simulations are used to study the surfaces of Cu 2 ZnSnSe 4 absorber layers. In particular, the effect of NH 4 OH and annealing under ambient conditions is investigated. We observe drastic changes in the measured quasi Fermi-level splitting (QFLs) after chemical cleaning of the absorber surface with NH 4 OH, which is traced back to a removal of the surface inversion. Air annealing recovers surface inversion, which reduces the recombination current at the surface. Annealing above 200 °C leads to a permanent change in the work function which cannot be modified by NH 4 OH etching anymore. This modification makes the QFLs insensitive to surface cleaning and explains why air annealing in Cu 2 ZnSnSe 4 is important. From numerical simulations we find that a large surface recombination velocity needs to be present in order to describe the experimental observations.
Type of Medium:
Online Resource
ISSN:
2045-2322
DOI:
10.1038/s41598-018-19798-w
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2018
detail.hit.zdb_id:
2615211-3
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