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Key Aspects of CdTe/CdS Solar Cells
Author(s) -
Durose K.,
Boyle D.,
Abken A.,
Ottley C.J.,
Nollet P.,
Degrave S.,
Burgelman M.,
Wendt R.,
Beier J.,
Bonnet D.
Publication year - 2002
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200201)229:2<1055::aid-pssb1055>3.0.co;2-w
Subject(s) - cadmium telluride photovoltaics , materials science , stoichiometry , grain size , annealing (glass) , doping , solar cell , photovoltaic system , impurity , optoelectronics , quantum efficiency , raw material , layer (electronics) , grain boundary , nanotechnology , metallurgy , chemistry , microstructure , electrical engineering , organic chemistry , engineering
Recent developments in the following areas are briefly reviewed: a) the electrical structure of grain boundaries in CdTe absorbers, b) impurities and non‐stoichiometry in CdTe solar cells and c) use of Sb 2 Te 3 in contacts to CdTe. Nominally identical solar cells fabricated using 99.999% pure CdTe feedstock from two different suppliers were compared. Differences in the photovoltaic response and absorber grain size were correlated with the purity of the feedstock, the purer material giving the higher V oc , FF and efficiency, and larger grain size. Quantum efficiency and C – V measurements indicated that the performance differences are most likely to result from reduced doping at the back contact surface in the less pure sample. A quantitative SIMS study of Sb–Te contacts to CdTe reveals that annealing in air at 400 °C causes an influx of Sb and O into the absorber layer. Free energy calculations indicate that this is driven by the preferential reaction of O with Sb compared to CdTe oxidation.