First-principles calculations for heterostructure studies Involving CsPbI3 perovskite and IV-VI semiconductors

Abstract

The PbX(X = S, Se, Te)/CsPbI3 heterostructure, formed by lead chalcogenides and halide perovskite CsPbI3, holds promise for optoelectronic devices. Utilizing first-principles calculations with VASP software, this study investigates its structural, electronic, and optical properties. With confirmed appropriate lattice mismatch rates (4.6%, 2.4%, 3.8%) and similar octahedral frameworks, constructing the PbX/CsPbI3 heterostructure is feasible. Calculations of electronic properties reveal mechanisms to improve optical performance. The type-I band alignment at the PbX/CsPbI3 interface(−5.27 eV < PbX < −3.73 eV, −5.34 eV < CsPbI3 < −3.57 eV) reduces electron and hole recombination losses, enhancing energy transfer efficiency. This arrangement facilitates electron and hole transfer from CsPbI3 to PbX, supported by charge density differences. Among the three heterostructures, PbSe/CsPbI3 demonstrates superior charge transfer capabilities, with more pronounced electron clouds. The PbX/CsPbI3 heterostructure extends CsPbI3’s light absorption into the near-infrared via PbX influence. Spectral comparison reveals PbTe/CsPbI3 > PbSe/CsPbI3 > PbS/CsPbI3, with PbSe/CsPbI3 excelling in stability, charge density transfer, and optical properties. Furthermore, under the premise of ensuring stability, different optical absorption characteristics can be achieved by adjusting the composition of Se atoms in PbSe/CsPbI3. This work provides a theoretical basis for the physical mechanisms behind enhancing the performance of PbX/CsPbI3 heterostructures as visible-to-near-infrared optoelectronic materials. It offers a promising avenue for the design of high-performance visible-to-near-infrared optoelectronic materials.