Exploring a novel Cu2ZnSnSe4-based metal chalcogenide heterostructure for energy storage application

Heterostructure materials based on transition metal chalcogenides are gaining significant attention due to their unique interfaces, robust structures, and synergistic effects, which have the potential to enhance energy production and extend the life span of energy storage devices. In this study, the Faradaic diffusion-limited and Faradaic diffusion non-limited electrochemical behavior of two PN junction semiconductors, CZTSe@CdS and CZTSe@ZnSe, were investigated using the microcapillary electrochemical method. Despite the promise of these materials, the complex relationship between heterostructure band theory and design strategies remains underexplored. The two PN junction semiconductors, were constructed using a straightforward electrodeposition method. Comprehensive characterization and first-principles calculations revealed that charge redistribution in the space charge region significantly enhances Faradaic activity and improves semiconductor conductivity. These improvements resulted in power densities of approximately 1.34 kW·cm −2 and energy densities of 54.84 Wh·cm −2 . This research highlights the crucial role of semiconductor theory in heterostructure design and demonstrates the potential of Faradaic PN junction composite materials for pseudocapacitive energy storage applications. • SnS, CdS, ZnSe integration on CZTSe enhanced areal capacitance and PCE. • Proposed PN junction improved the conversion and storage energy of absorbed layer. • Faradaic diffusion is the dominant mechanism for both SnS@CZTSe@CdS/ZnSe. • SnS@CZTSe@CdS/ZnSe demonstrated a wide electrochemical stability window.