Dresden 2011 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 39: Photovoltaics: Chalcopyrites I
HL 39.1: Talk
Tuesday, March 15, 2011, 13:30–13:45, FOE Anorg
Excess carrier depths profiles in Cu(In,Ga)(S,Se)2 absorbers from spectral photoluminescence — •Nils Könne1, Sebastian Knabe1, Wolfram Witte2, Dimitrios Hariskos2, Alexander Meeder3, and Gottfried H. Bauer1 — 1Institute of Physics, CvO University Oldenburg, Germany — 2Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Stuttgart, Germany — 3SULFURCELL Solartechnik GmbH, Berlin, Germany
The polycrystalline structure of chalcopyrite absorbers, such as Cu(In,Ga)(S,Se)2 and their complex metallurgical composition results in lateral and depth dependent inhomogeneities. The spectral photoluminescence (PL) recorded from front and rear side of these chalcopyrite thin-film systems shows a distinct different behavior in particular of the high energy PL-wing which is strongly governed by absorption/emission approaching unity, as well as by re-absorption of emitted PL-photons and their depth dependent origin, say excess carrier depth profile. We define a contrast parameter for the high energy PL-yield of the fluxes recorded from front side and rear side and we proof the origin of the experimental contrast with numerical simulations of spectral PL-yields via Planck’s generalized law for different depth profiles of excess carriers and band gap/absorption coefficients. By comparison of experimental contrast parameters with results from numerical simulations we conclude a set of regimes of realistic combinations of depth profiles for excess carriers and band gaps.