A Versatile Solution Route to Efficient Cu₂ZnSn(S,Se)₄ Thin-Film Solar Cells

Abstract

A simple solution-based approach for the deposition of Cu 2 ZnSn(S,Se) 4 using an amine−thiol mixture is presented. The versatility of this solvent mixture in dissolving different cation sources and chalcogens opens the door for a variety of metal chalcogenide molecular precursor designs. The process involves incorporating the metal sources and chalcogens into an amine−thiol solvent mixture at room temperature, spin coating a precursor film, and heat-treating precursor films in both an inert gas and selenium atmosphere. With this solution approach, high-quality kesterite CZTS and CZTSSe thin films were formed after low-temperature annealing and selenization. Solar cells were fabricated based on these CZTSSe thin films, resulting in a total area power conversion efficiency of 7.86% for a cell area of 0.47 cm 2 under standard AM 1.5 illumination.

Non-toxic precursor solution route for fabrication of CZTS solar cell based on all layers solution processed

“…For CZTS absorber layer, compared to the colloidal nanoparticles deposition, precursor solution deposition has the advantage of compositional uniformity due to atomic level mixing of elements. Further, the precursor solution method circumvents nanoparticles synthesis step and provides controllable film morphology [15][16][17][18][19]. In order to prepare non-toixc CZTS absorber layer deposition, numerous green chemistry or non-toxic approaches have been developed to synthesize semiconductors nanoparticles or precursor film [6,[19][20][21].…”

Easy and low-cost aqueous precipitation method to obtain Cu2ZnSn(S, Se)4 thin layers

“…In this regards, many others hydrazine-free preparations route have been tested. Low-toxic organic solvents have been used for direct deposition of absorber layer as alcohols 12,13 , amines 14 and dimethyl sulfoxide (DMSO) 15 with high efficiency over 10% 16 . Even a water-ethanol mixture was developed with good results 17 .…”

Solution-Processed Cu2ZnSn(S,Se)4 Thin-Film Solar Cells Using Elemental Cu, Zn, Sn, S, and Se Powders as Source

“…However, as a result of the high toxicity and dangerous instability of explosible hydrazine, the non-hydrazine solvent is more desirable for practical application. Therefore, some non-hydrazine solvents, such as the mixtures of ethanol and water and amine-thiol mixture, have been tried presently to dissolve the metallic oxide or metal salt for preparing the CZTS precursor solution [26][27][28].…”