Device Simulation of BaZrSe3-Based Chalcogenide Perovskite Solar Cells

The large-scale application of traditional lead-based halide perovskite solar cells (PSCs) has been hindered by their environmental risks associated with toxic lead ions, driving the urgent exploration of efficient and eco-friendly alternatives. Compared to earlier simulation studies on chalcogenide perovskite solar cells, we propose chalcogenide perovskite BaZrSe3 (Eg = 1.11−1.34 eV) as a non-toxic, cost-effective, and stable absorber layer for chalcogenide perovskite solar cells (CPSCs) and innovatively introduce back surface field (BSF) technology to significantly enhance device performance. Through systematic device simulations, the photovoltaic performance of devices with two different electron transport layers (ETLs), TiO2 and SnS2, was compared, and critical parameters including absorber thickness, charge transport layer (CTL) energy alignment, operating temperature, parasitic resistance, and light-intensity dependency were optimized comprehensively. This approach achieved over 100% PCE enhancement in devices with three distinct bandgaps. Furthermore, back-surface field (BSF) engineering was implemented at the absorber/hole transport layer (HTL) interface. By evaluating five BSF materials, we demonstrate that a CdTe interlayer effectively suppresses carrier non-radiative recombination at the BaZrSe3/HTL interface. For the device with Eg = 1.11 eV of the absorber layer, the PCE increased from 27.57% to 32.49%, accompanied by a VOC of 0.84 V and a FF of 84.93%. This study not only validates the feasibility of BaZrSe3 as a high-performance CPSCs absorber but also provides theoretical insights and interfacial band-alignment strategies for designing eco-friendly, lead-free perovskite photovoltaics.