Silicon-based van der Waals heteroepitaxy of PbSe with room-temperature sensitive mid-infrared response

Silicon integration of non-silicon semiconductors is always challenging due to the serious lattice and thermal expansion mismatch. In this study, we design a silicon-based van der Waals heteroepitaxy of infrared semiconductors through the graphene buffer layer. Through density functional theory calculations, we demonstrate that graphene-modified SiO2 surfaces exhibit a drastic reduction in surface potential and sliding energy compared to unmodified substrates. These properties enable the epitaxial growth of high-quality single-crystal lead selenide (PbSe) on silicon, effectively circumventing conventional substrate-induced constraints. The photoelectric characterization shows that the detector made from the graphene/silicon-based PbSe structure achieves great mid-infrared performance. It has a room-temperature specific detectivity (D*) of up to 1.4 × 109 cm Hz1/2 W−1 and a rapid response time in the microsecond range. Our work offers a scalable pathway to overcome limitations of lattice-matched epitaxy and advance the development of silicon-compatible optoelectronics.