AVS 59th Annual International Symposium and Exhibition
    Electron Transport at the Nanoscale Focus Topic Friday Sessions
       Session ET+SS+GR+SP-FrM

Paper ET+SS+GR+SP-FrM3
Mapping Solar Cell Internal Fields and Band Offsets

Friday, November 2, 2012, 9:00 am, Room 16

Session: Electron Transport at the Nanoscale: Development of Theories and Techniques
Presenter: H. Cohen, Weizmann Institute of Science, Israel
Authors: H. Cohen, Weizmann Institute of Science, Israel
Y. Itzhaik, Weizmann Institute of Science, Israel
G. Hodes, Weizmann Institute of Science, Israel
Correspondent: Click to Email
The internal fields and band offsets across device interfaces are key features in various applications and, yet, this information is generally inaccessible by standard electrical tools. A systematic approach addressing this problem is demonstrated here, based on chemically resolved electrical measurements (CREM). Studying nanoporous photovoltaic cells, we resolve the internal details layer-by-layer and, thus, extract a realistic band diagram for the multi-interfacial structure. We show the spontaneous evolution of two p-n–like junctions and quantify the associated band bending at corresponding domains. An account for the ‘real’ working conditions of the device is attempted by exposing the cell to optical and electrical stimuli, revealing the charge trapping at each specific layer and showing how certain sample treatments affect the trapping mechanisms. Our methodology overcomes a critical missing link in device characterization and in fundamental studies of nanoscale solid-state devices.