Photovoltaic Possibility of Cu2SiSe3 and Cu2SnS3 Ternary Chalcogenides- Single Junction to Tandem Architecture

TL;DR

This study evaluates Cu2SiSe3 and Cu2SnS3 ternary chalcogenides for photovoltaic applications, demonstrating high efficiency single junction and tandem solar cell configurations through drift diffusion modeling.

Contribution

It introduces a detailed simulation analysis of Cu2SiSe3 and Cu2SnS3 based solar cells, including tandem architectures, highlighting their potential for high-efficiency photovoltaics.

Findings

Single junction Cu2SiSe3 device achieves 18.13% efficiency.

Cu2SnS3 device achieves 15.59% efficiency.

Tandem architecture reaches 24.1% efficiency, surpassing single junctions.

Abstract

Cu based ternary chalcogenides are gathering attention for sustainable energy applications due to their reduced complexity compared to quaternary alternatives. We used drift diffusion modeling to evaluate the feasibility of photovoltaics employing ternary chalcogenide absorbers based on Cu2SiSe3 and Cu2SnS3. The device metrics are evaluated by analyzing absorber layer thickness intrinsic carrier concentration defect density and energy band alignment at interfacial junctions. The optimized single junction Cu2SiSe3 based device configuration achieves a power conversion efficiency of 18.13 percent exhibiting a short circuit current density of 38 mA cm^-2 and an open circuit voltage of 0.64 V. The Cu2SnS3 based device achieves an efficiency of 15.59 percent with a short circuit current density of 48.8 mA cm^-2 and an open circuit voltage of 0.42 V. We examined the impact of the buffer layer on device parameters uncovering further avenues for performance improvement. Additionally we simulated a two terminal tandem solar cell using Cu2SiSe3 Eg 1.44 eV in the upper cell to capture photons from the visible spectrum and Cu2SnS3 Eg 0.91 eV in the lower cell to absorb from the infrared spectrum. The simulated tandem architecture, featuring a VOC of 1.24 V a JSC of 24.6 mA cm^-2 a fill factor (FF) of 79.2 percent and an efficiency of 24.1 percent markedly surpassed conventional single junction devices demonstrating the viability of Cu2SiSe3-Cu2SnS3 absorber-based tandem solar cells for next generation high-efficiency solar technologies.