@article{BeckerBluemBonneschkyetal., author = {Becker, Gerd and Bl{\"u}m, Stefan and Bonneschky, Alexis and Kruska, Martin}, title = {Nutzung energetischer Kennziffern}, abstract = {Kennziffern dienen als Bewertungsgr{\"o}ße f{\"u}r den Verbrauch von Stoff- und Energiemengen. Ihr Reiz liegt darin, scheinbar mit Hilfe einfach zu gewinnender Zahlen und eines anschließenden Vergleiches mit Standardwerten relativ rasch eine Aussage {\"u}ber die Qualit{\"a}t eines komplexen Prozesses machen zu k{\"o}nnen. Gerade wegen dieser einfachen Erstellung sind auch die Grenzen dieses Verfahrens zu erkennen}, language = {de} } @misc{BaerSchubertMarsenetal., author = {B{\"a}r, Marcus and Schubert, Bj{\"o}rn-Arvid and Marsen, Bj{\"o}rn and Wilks, Regan G. and Pookpanratana, Sujitra and Blum, Monika and Krause, Stefan and Unold, Thomas and Yang, Wan Li and Weinhardt, Lothar and Heske, Clemens and Schock, Hans-Werner}, title = {Cliff-like conduction band offset and KCN-induced recombination barrier enhancement at the CdS/Cu2ZnSnS4 thin-film solar cell heterojunction}, abstract = {The electronic structure of the CdS/Cu2ZnSnS4 (CZTS) heterojunction was investigated by direct and inverse photoemission. The effects of a KCN etch of the CZTS absorber prior to CdS deposition on the band alignment at the respective interface were studied. We find a "cliff"-like conduction band offset at the CdS/CZTS interface independent of absorber pretreatment and a significant etch-induced enhancement of the energetic barrier for charge carrier recombination across the CdS/CZTS interface.}, language = {en} } @misc{BaerKlaerWeinhardtetal., author = {B{\"a}r, Marcus and Klaer, Joachim and Weinhardt, Lothar and Wilks, Regan G. and Krause, Stefan and Blum, Monika and Yang, Wan Li and Heske, Clemens and Schock, Hans-Werner}, title = {Cu 2-x S Surface Phases and Their Impact on the Electronic Structure of CuInS 2 Thin Films - A Hidden Parameter in Solar Cell Optimization}, series = {Advanced Energy Materials}, volume = {3}, journal = {Advanced Energy Materials}, number = {6}, issn = {1614-6840}, pages = {777 -- 781}, abstract = {The surface properties of CuInS 2 (CIS) thin-fi lm solar cell absorbers are investigated by a combination of electron and soft X-ray spectroscopies. Spatially separated regions of varying colors are observed and identifi ed to be dominated by either CuS or Cu 2 S surface phases. After their removal by KCN etching, the samples cannot be distinguished by eye and the CIS surface is found to be Cu-defi cient in both regions. However, a signifi cantly more pronounced off-stoichiometry in the region initially covered by Cu 2 S can be identifi ed. In this region, the resulting surface band gap is also signifi cantly larger than the E g Surf of the initially CuS-terminated region. Such variations may represent a hidden parameter which, if overlooked, induces irreproducibility and thus prevents systematic optimization efforts.}, language = {en} }