Rubidium distribution at atomic scale in high efficient Cu(In,Ga)Se2thin-film solar cells

Arantxa Vilalta-Clemente (1) , Mohit Raghuwanshi (1, 2) , Sébastien Duguay (1) , Celia Castro (1) , Emmanuel Cadel (1) , Philippe Pareige (1) , Philip Jackson (3) , Roland Wuerz (3) , Dimitrios Hariskos (3) , Wolfram Witte (3)

1 GPM - Groupe de physique des matériaux
2 RWTH - Rheinisch-Westfälische Technische Hochschule Aachen University
3 ZSW - Zentrum fur Sonnenenergie-und Wasserstoff-Forschung

The introduction of a rubidium fluoride post deposition treatment (RbF-PDT) for Cu(In,Ga)Se2 (CIGS) absorber layers has led to a record efficiency up to 22.6% for thin-film solar cell technology. In the present work, high efficiency CIGS samples with RbF-PDT have been investigated by atom probe tomography (APT) to reveal the atomic distribution of all alkali elements present in CIGS layers and compared with non-treated samples. A Scanning Electron Microscopy Dual beam station (Focused Ion Beam–Gas Injection System) as well as Transmission Kikuchi diffraction is used for atom probe sample preparation and localization of the grain boundaries (GBs) in the area of interest. The analysis of the 3D atomic scale APT reconstructions of CIGS samples with RbF-PDT shows that inside grains, Rb is under the detection limit, but the Na concentration is enhanced as compared to the reference sample without Rb. At the GBs, a high concentration of Rb reaching 1.5 at. % was found, and Na and K (diffusing from the glass subs...

Domaines: Physique [physics]

Arantxa Vilalta-Clemente, Mohit Raghuwanshi, Sébastien Duguay, Celia Castro, Emmanuel Cadel, et al.. Rubidium distribution at atomic scale in high efficient Cu(In,Ga)Se2thin-film solar cells. Applied Physics Letters, 2018, 112 (10), pp.103105. ⟨10.1063/1.5020805⟩. ⟨hal-01929133⟩