Rubidium Fluoride Absorber Treatment for Wide-Gap (Ag,Cu)(In,Ga)Se2 Solar Cells
Artikel i vetenskaplig tidskrift, 2022

This contribution studies the potential of an RbF postdeposition treatment (RbF-PDT) of wide-gap (Ag,Cu)(In,Ga)Se2 (ACIGS) absorbers to improve the corresponding solar cell performance. While a higher open-circuit voltage (VOC) and short-circuit current density are achieved, a lower fill factor (FF) is observed for most of the devices subjected to an RbF-PDT. However, the drop in FF can be avoided for some close-stoichiometric samples, leading to maximum efficiencies beyond 16% (without antireflection coating) at a bandgap energy (Eg) of 1.43 eV. For off-stoichiometric ACIGS, a record VOC value of 926 mV at Eg = 1.44 eV is reached. Lower VOC deficits likely require enhanced bulk quality of wide-gap chalcopyrite absorbers. Extensive material analysis shows that the heavy alkali PDT of ACIGS with high Ag and Ga contents leads to similar absorber modifications as commonly observed for low-gap Cu(In,Ga)Se2 (CIGS). Rubidium is continuously distributed at “internal” (grain boundaries) and “external” (buffer and back contact) absorber interfaces. The results indicate that Rb diffusion into the absorber bulk (including 1:1:2 and 1:3:5 compounds) is restricted. Furthermore, the formation of a very thin RbInSe2 surface layer is suggested. It remains open, which effects alter the device characteristics after RbF-PDT.

RbF postdeposition treatment (RbF-PDT)

wide-gap chalcopyrite

Cu(In,Ga)Se (CIGS) 2


(Ag,Cu)(In,Ga)Se (ACIGS) 2


Jan Keller

Uppsala universitet

Hisham Aboulfadl

Chalmers, Fysik, Mikrostrukturfysik

Lars Stolt

Uppsala universitet

Olivier Donzel-Gargand

Uppsala universitet

Marika Edoff

Uppsala universitet

Solar RRL

2367198X (eISSN)

Vol. In Press

Styrning av gradienter i tunnfilmssolceller

Stiftelsen för Strategisk forskning (SSF) (RMA15-0030), 2016-05-01 -- 2021-06-30.



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