Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Jessica de Wild; Gizem Birant; Guy Brammertz; Marc Meuris; Jef Poortmans; Bart Vermang

LAPSE

Living Archive for Process Systems Engineering

LAPSE:2023.33690

Published Article

LAPSE:2023.33690

Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector

Jessica de Wild, Gizem Birant, Guy Brammertz, Marc Meuris, Jef Poortmans, Bart Vermang

April 21, 2023

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.

Record ID

LAPSE:2023.33690

Keywords

AlOx, Cu(In,Ga)Se2, optical enhancement, passivation, silver doping, ultrathin films

Subject

Materials

Suggested Citation

de Wild J, Birant G, Brammertz G, Meuris M, Poortmans J, Vermang B. Ultrathin Cu(In,Ga)Se2 Solar Cells with Ag/AlOx Passivating Back Reflector. (2023). LAPSE:2023.33690

Author Affiliations

de Wild J: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Institute for Materials Research in MicroElectronics (IMOMEC), Hasselt University IMEC (Partner in Solliance), Wetenschapspark 1
Birant G: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Institute for Materials Research in MicroElectronics (IMOMEC), Hasselt University IMEC (Partner in Solliance), Wetenschapspark 1 [ORCID]
Brammertz G: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Institute for Materials Research in MicroElectronics (IMOMEC), Hasselt University IMEC (Partner in Solliance), Wetenschapspark 1
Meuris M: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Institute for Materials Research in MicroElectronics (IMOMEC), Hasselt University IMEC (Partner in Solliance), Wetenschapspark 1
Poortmans J: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Energyville, Thor Park 8320, 3600 Genk, Belgium; Interuniversity MicroElectronics Centre (IMEC) (Partner in Solliance), Kapeldre
Vermang B: Institute for Material Research (IMO), Hasselt University (Partner in Solliance), Wetenschapspark 1, 3590 Diepenbeek, Belgium; Institute for Materials Research in MicroElectronics (IMOMEC), Hasselt University IMEC (Partner in Solliance), Wetenschapspark 1

Journal Name

Energies

Volume

14

Issue

14

First Page

4268

Year

2021

Publication Date

2021-07-14