TY - JOUR
T1 - S-Te interdiffusion within grains and grain boundaries in cdte solar cells
AU - Li, C.
AU - Poplawsky, J.
AU - Paudel, N.
AU - Pennycook, T. J.
AU - Haigh, S. J.
AU - Al-Jassim, M. M.
AU - Yan, Y.
AU - Pennycook, S. J.
PY - 2014
Y1 - 2014
N2 - At the CdTe/CdS interface, a significant Te-S interdiffusion has been found a few nanometers into the CdTe grain interiors with scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy. This interdiffusion happens on both as-grown and CdCl2-treated CdTe. S substitution at Te sites has been directly resolved in CdTe with STEM Z-contrast images, which further confirms the S diffusion into CdTe grain interiors. Moreover, when a sufficient amount of S substitutes for Te, a structural transformation from zinc-blende to wurtzite has been observed. In the CdCl2-treated CdTe, Cl segregation has also been found at the interface. STEM electron-beam-induced current shows that the p-n junction occurs a few namometers into the CdTe grains, which is consistent with the S diffusion range we observe. The shift of the p-n junction suggests a buried homojunction which would help reduce nonradiative recombination at the junction. Meanwhile, long-range Sdiffusion in CdTe grain boundaries (GBs) has been detected, as hasTe and Cl diffusion in CdS GBs.
AB - At the CdTe/CdS interface, a significant Te-S interdiffusion has been found a few nanometers into the CdTe grain interiors with scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy. This interdiffusion happens on both as-grown and CdCl2-treated CdTe. S substitution at Te sites has been directly resolved in CdTe with STEM Z-contrast images, which further confirms the S diffusion into CdTe grain interiors. Moreover, when a sufficient amount of S substitutes for Te, a structural transformation from zinc-blende to wurtzite has been observed. In the CdCl2-treated CdTe, Cl segregation has also been found at the interface. STEM electron-beam-induced current shows that the p-n junction occurs a few namometers into the CdTe grains, which is consistent with the S diffusion range we observe. The shift of the p-n junction suggests a buried homojunction which would help reduce nonradiative recombination at the junction. Meanwhile, long-range Sdiffusion in CdTe grain boundaries (GBs) has been detected, as hasTe and Cl diffusion in CdS GBs.
KW - CdTe
KW - interface scanning transmission electron microscopy
KW - thin-film photovoltaic
UR - http://www.scopus.com/inward/record.url?scp=84908231902&partnerID=8YFLogxK
U2 - 10.1109/JPHOTOV.2014.2351622
DO - 10.1109/JPHOTOV.2014.2351622
M3 - Article
AN - SCOPUS:84908231902
SN - 2156-3381
VL - 4
SP - 1636
EP - 1643
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
IS - 6
M1 - 6905708
ER -
