Alkali treatment for single-stage co-evaporated thin CuIn0.7Ga0.3Se2 solar cells

THIN SOLID FILMS

卷:671

Article; Proceedings Paper

de Wild, J.^1,2  Simor, M.³  Buldu, D. G.^1,2  Kohl, T.^1,2  Brammertz, G.^1,2  Meuris, M.^1,2  Poortmans, J.^1,4,5  Vermang, B.^1,2 

[1] Hasselt Univ, Inst Mat Res IMO, Solliance & EnergyVille, Agoralaan Gebouw H, B-3590 Diepenbeek, Belgium

[2] Imec Div IMOMEC, Solliance & EnergyVille, Wetenschapspk 1, B-3590 Diepenbeek, Belgium

[3] TNO Solliance, High Tech Campus 21, NL-5656 AE Eindhoven, Netherlands

[4] IMEC, Solliance & EnergyVille, Kapeldreef 75, B-3001 Leuven, Belgium

[5] Katholieke Univ Leuven, Dept Elect Engn, Kasteelpk Arenberg 10, B-3001 Heverlee, Belgium

关键词: Copper indium gallium selenide;    Solar cells;    Single-stage;    Alkali treatment;    Thin film;    Co-evaporation;   

DOI  :  10.1016/j.tsf.2018.12.022

来源: Elsevier

【 摘 要 】

KF and NaF treatments were done for single-stage co-evaporated CuIn0.7Ga0.Se-3(2). The absorber layers were grown on a substrate with an alkali barrier layer and NaF was either added before or after absorber layer growth. No differences were found on the device performance amongst the procedures to add Na. This is expected if the single-stage process does not have a copper rich stage or a Ga gradient, which is likely since there was no change of the elemental fluxes during absorber layer growth and no Ga profile was measured. KF was added by post-deposition only. Current-voltage characteristics were measured and net doping concentrations were determined from capacitance-voltage measurements (CV). We see an improvement of the open-circuit voltage (V-oc) with increasing KF amount, and a marginal increase of the fill factor. CV measurements showed increasing net acceptor concentration with increasing KF amount. Time resolved photoluminescence (PL) showed an increased decay time for KF treated cells and the PL peak shape changed. Without KF treatment the PL peak is symmetric, after KF treatment a further peak appears at higher energy in the PL spectrum. This higher energy peak increases in intensity with increasing KF concentration. The same effects were seen in a sample without Na, but here the Voc was limited due to large tailing. Hence both Na and K are required for good cell efficiencies.

【 授权许可】

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