Open AccessStructural and compositional dependence of the CdTexSe1−x alloy layer photoactivity in CdTe-based solar cells
Author(s) -
Jonathan D. Poplawsky,
Wei Guo,
Naba R. Paudel,
Amy Ng,
Karren L. More,
Donovan N. Leonard,
Yanfa Yan
Publication year - 2016
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/ncomms12537
Subject(s) - wurtzite crystal structure , alloy , materials science , cadmium telluride photovoltaics , solar cell , band gap , layer (electronics) , quantum efficiency , transmission electron microscopy , optoelectronics , semiconductor , nanotechnology , composite material , metallurgy , zinc
The published external quantum efficiency data of the world-record CdTe solar cell suggests that the device uses bandgap engineering, most likely with a CdTe x Se 1− x alloy layer to increase the short-circuit current and overall device efficiency. Here atom probe tomography, transmission electron microscopy and electron beam-induced current are used to clarify the dependence of Se content on the photoactive properties of CdTe x Se 1− x alloy layers in bandgap-graded CdTe solar cells. Four solar cells were prepared with 50, 100, 200 and 400 nm-thick CdSe layers to reveal the formation, growth, composition, structure and photoactivity of the CdTe x Se 1− x alloy with respect to the degree of Se diffusion. The results show that the CdTe x Se 1− x layer photoactivity is highly dependent on the crystalline structure of the alloy (zincblende versus wurtzite), which is also dependent on the Se and Te concentrations.