用于可见光太阳能光伏应用的SrMnO3立方钙钛矿的光电性能评估

Abstract Next-generation solar cell materials with superior optoelectronic and photovoltaic properties must circumvent the toxicity and degradation issues of hybrid lead halide perovskites. In this regard, transition metal oxide perovskites with favourable optoelectronic properties are of significant relevance. In this work, we report a combined theoretical–experimental investigation into the optoelectronic properties of cubic-perovskite, SrMnO 3 (SMO) for prospective visible-light photovoltaic application. Using first-principles density functional theory calculations, we show that SMO with cubic symmetry demonstrates a direct bandgap character (∼0.62 eV), exceptional absorption behaviour (∼10 5 cm −1 in the visible range), substantial dielectric constant (∼11) and a reasonably small exciton binding energy (∼44 meV) promising a sizeable photovoltaic response (PCE SLME ∼ 16 %). Accordingly, thin films of SMO were grown on fluorine-doped tin oxide (FTO) coated glass substrate using pulsed laser deposition (PLD) technique. Structural characterization demonstrated phase pure SMO with cubic symmetry. Room-temperature Hall measurement allowed the determination of the nature (p-type) and concentration (1.37 × 10 12 cm −3 ) of majority charge carriers, conductivity (5.56 × 10 − ⁶ S/cm), and carrier mobility (24.5 cm 2 /V·s) which are reasonably comparable to those of archetypal halide perovskite , CH 3 NH 3 PbI 3 (MAPbI 3 ). Ultraviolet photoelectron spectroscopy further allowed the determination of energies corresponding to valence and conduction band edges, crucial for device fabrication. Initial device characterization demonstrates small yet finite photovoltaic response, suggesting the requirement of thorough optimization of the device fabrication parameters and development of a suitable hole transport layer.