Kesterite; Electrodeposition; ZnSe secondary phase; Short circuit current density; Photocurrent spectroscopy; EQE
Abstract :
[en] Absorber layers consisting of Cu2ZnSnSe4 (CZTSe) and surface ZnSe in variable ratios were
prepared by selenization of electroplated Cu/Sn/Zn precursors and completed into full devices with up to 5.6 % power conversion efficiency. The loss of short circuit current density for samples with increasing ZnSe content is consistent with an overall reduction of spectral response, pointing to a ZnSe current blocking behavior. A feature in the spectral response centered around 3 eV was identified and attributed to light absorption by ZnSe. A model is proposed to account for additional collection of the carriers generated underneath ZnSe capable of diffusing across to the space charge region. The model satisfactorily reproduces the shape of the spectral response and the estimated ZnSe surface coverage is in good qualitative agreement with analysis of the Raman spectral mapping. The model emphasizes the importance of the ZnSe morphology on the spectral response, and its consequences on the solar cell device performance.
Disciplines :
Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others
Author, co-author :
Colombara, Diego ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Robert, Erika ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Crossay, Alexandre ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Taylor, Aidan; Durham University > Department of Physics
Guennou, Mael; Centre de Recherche Public Gabriel Lippmann - Luxembourg > Département Science et Analyse des Matériaux
Arasimowicz, Monika ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Malaquias, Joao Corujo Branco ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Djemour, Rabie ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Dale, Phillip ; University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit
Language :
English
Title :
Quantification of surface ZnSe in Cu2ZnSnSe4-based solar cells by analysis of the spectral response
FP7 - 284486 - SCALENANO - Development and scale-up of nanostructured based materials and processes for low cost high efficiency chalcogenide based photovoltaics