Title :
Study on the interfacial structure and junction depth of polycrystalline Cu(In,Ga)Se2 devices
Author :
Nelson, Art J. ; Gabor, A.M. ; Contreras, M.A. ; Tuttle, J.R. ; Noufi, R. ; Kumar, P. Asoka ; Lynn, K.G.
Author_Institution :
Nat. Renewable Energy Lab., Golden, CO, USA
Abstract :
X-ray photoemission spectroscopy (XPS) and positron annihilation spectroscopy (PAS) have been used to characterize the surface-versus-bulk composition, electronic, and physical structure of polycrystalline Cu(In,Ga)Se2 thin-film solar cell device interfaces. Angle-resolved high resolution photoemission measurements on the valence band electronic structure and Cu 2p, In 3d, Ga 2p, and Se 3d core lines were used to evaluate the surface and near-surface chemistry of CuInSe2 and Cu(In,Ga)Se2 device-grade thin films. XPS compositional depth profiles were also acquired from the near-surface region. PAS was used as a nondestructive, depth-sensitive probe for open-volume-type defects. Results of these measurements are related to device efficiencies to show the effects of compositional variations and defect concentrations in the near-surface region on device performance
Keywords :
X-ray photoelectron spectra; copper compounds; defect states; gallium compounds; indium compounds; nondestructive testing; p-n heterojunctions; positron annihilation; semiconductor device testing; solar cells; Cu(In,Ga)Se2 thin-film solar cells; CuInGaSe2; CuInSe2; NDT; X-ray photoemission spectroscopy; angle-resolved high resolution photoemission measurements; compositional variations; defect concentrations; depth profiles; device efficiencies; electronic structure; interfacial structure; junction depth; measurements; near-surface chemistry; open-volume-type defects; performance; physical structure; polycrystalline semiconductor; positron annihilation spectroscopy; surface chemistry; surface-versus-bulk composition; valence band; Chemical vapor deposition; Energy resolution; Laboratories; Lattices; Photoelectricity; Positrons; Probes; Spectroscopy; Thin film devices; Transistors;
Conference_Titel :
Photovoltaic Energy Conversion, 1994., Conference Record of the Twenty Fourth. IEEE Photovoltaic Specialists Conference - 1994, 1994 IEEE First World Conference on
Conference_Location :
Waikoloa, HI
Print_ISBN :
0-7803-1460-3
DOI :
10.1109/WCPEC.1994.519862
