\CIGS\ J???V distortion in the absence of blue photons

Title \CIGS\ J?��V distortion in the absence of blue photons
Author: Pudov, A O; Sites, J R; Contreras, M A; Nakada, T & Schock, H.-W.
Thin Solid Films, 2005
2005
http://www.sciencedirect.com/science/article/pii/S0040609004016281
More details: Common buffer materials used with CuInGaSe2 (CIGS) absorbers produce conduction-band barriers that may significantly distort the current?��voltage (J?��V) curves, especially when short-wavelength photons are excluded from the illumination spectrum. Earlier work documented this effect for CuInSe2 (CIS) absorbers (band gap near 1.0 eV) with CdS buffers. Higher band-gap (?�?1.15 eV) \{CIGS\} absorbers show little or no distortion with CdS buffer layers. However, wider band gap (lower electron affinity) ZnS(O,OH) or InS(O,OH) buffers, prepared by chemical-bath deposition (CBD), clearly show the J?��V distortion. The distortions have a turn-on time constant the order of a minute and turn-off time constant the order of a day, and they correlate with major variations in apparent quantum efficiency (QE) measured with varying intensity and spectral content of bias light. The results are consistent with a conduction-band spike barrier that increases with buffer band gap and is larger when the electron concentration in the buffer is small. Blue photons,CuInGaSe2,CuInSe2

\{EMRS\} 2004 Proceedings of Symposium O on Thin Film Chalcogenide Photovoltaic Materials, \{EMRS\} 2004 Conference, Strasbourg, France, May 24-28, 2004