InGaAs Nanomembrane/Si van der Waals Heterojunction Photodiodes with Broadband and High Photoresponsivity.

Development of broadband photodetectors is of great importance for applications in high-capacity optical communication, night vision, and biomedical imaging systems. While heterostructured photodetectors can expand light detection range, fabrication of heterostructures via epitaxial growth or wafer bonding still faces significant challenges because of problems such as lattice and thermal mismatches. Here, a transfer printing technique is used for the heterogeneous integration of InGaAs nanomembranes on silicon semiconductors and thus the formation of van der Waals heterojunction photodiodes, which can enhance the spectral response and photoresponsivity of Si photodiodes. Transfer-printed InGaAs nanomembrane/Si heterojunction photodiode exhibits a high rectification ratio (7.73 × 104 at ±3 V) and low leakage current (7.44 × 10-5 A/cm2 at -3 V) in a dark state. In particular, the photodiode shows high photoresponsivities (7.52 and 2.2 A W-1 at a reverse bias of -3 V and zero bias, respectively) in the broadband spectral range (400-1250 nm) and fast rise-fall response times (13-16 ms), demonstrating broadband and fast photodetection capabilities. The suggested III-V/Si van der Waals heterostructures can be a robust platform for the fabrication of high-performance on-chip photodetectors compatible with Si integrated optical chips.