Elaboration of wide bandgap CIGS on silicon by electrodeposition of stacked metal precursors and sulfur annealing for tandem solar cell applications

• Published in: EPJ Photovoltaics Vol. 11; p. 11
• Main Authors: Crossay, Alexandre, Cammilleri, Davide, Thomere, Angelica, Zerbo, Bienlo, Rebai, Amelle, Barreau, Nicolas, Lincot, Daniel
• Format: Journal Article
• Language: English
• Published: Les Ulis EDP Sciences 2020; EDP sciences
• Subjects: Annealing; Bilayers; Condensed Matter; Copper; Copper indium gallium selenides; Efficiency; Electrodeposition; Electrolytes; High temperature; Indium; Materials Science; Metals; Photoluminescence; Photovoltaic cells; Physics; Precursors; pure sulfide cigs; Silicon; Silicon substrates; Silver; silver-sulfide; Solar cells; Spectrum analysis; Sulfur; tandem solar cells; Thin films; silicon; Tandem solar cells; electrodeposition; silver-sulfide; pure sulfide CIGS
• ISSN: 2105-0716; 2105-0716
• DOI: 10.1051/epjpv/2020008

A method was developed for the electrodeposition of Cu-In-Ga precursor layers to elaborate Cu(In,Ga)(S,Se) 2 (CIGS) thin films on silicon substrates for future application as silicon/wide-gap CIGS tandem solar cells. An underlayer of Ag was first deposited on silicon substrates to ensure a good adhesion of the electrodeposited stack and to serve as cathode during the deposition process. Cu, In and Ga layers were then sequentially electrodeposited. Ag-Cu-In-Ga precursor layers were finally subjected to elemental sulfur annealing at 600 °C. Formation of compact and adherent AgCIGS is observed. X ray diffraction and photoluminescence analyses confirm the formation of wide-gap CIGS of about 1.6 eV, with a spontaneous gallium grading over the depth of the sample leading to the formation of a bi-layer structure with a gallium rich layer at the interface with silicon.