The interplay between optoelectronic and magnetic properties in Co-doped Cu₂ZnSnS₄ for next-generation solar cell devices

A search for next-generation solar cell devices to massively actualize renewable energy is being exponentially conducted. It includes the development of Cu₂ZnSnS₄ (CZTS)-based solar cells, which are known as cost-effective and highly stable solar cell devices. In this present research, we develop a CZTS solar cell by adding a magnetic degree of freedom using cobalt (Co) doping. We find that the Co doping can induce modulation of the crystalline structure and bandgap of CZTS, which further influences its photovoltaic performance. The increase in the grain size of the CZTS with the addition of Co doping could further induce the reduction of detrimental grain boundaries, which benefits the photovoltaic performance of CZTS-based solar cells. Co doping also generates magnetic behavior in CZTS, which supports its magnetically controlled optoelectronic properties and thus, in turn, enhances the photovoltaic performance. We believe that this study could open up opportunities to obtain next-generation solar cell devices with excellent performances by using magnetic-field induction.