Perovskite quantum dots/WSe2 mixed-dimensional van der Waals heterostructure for photoelectric enhancement and polarization sensitivity

Abstract

The performance of some heterostructures based devices is limited by strong interlayer coupling and limited electronic structure modulation. Meanwhile, the detection of polarized light holds great significance in future photoelectric fields such as cryptography. In this work, zero-dimensional/two-dimensional (0D/2D) mixed-dimensional van der Waals heterostructure (MvdWH) polarization-sensitive photodetector composed of solution-synthesized CH3NH3PbI3(MAPbI3) perovskite quantum dots (QDs) and chemical vapor deposition (CVD)-grown WSe2 was designed, forming a type II band structure. The MvdWH effectively enhance the carrier transmission rate, and improve the efficiency of charge separation, realizing an ultra-high responsiveness of 217.8 A/W and an ultrasensitive photodetectivity of 2.56 × 1011 Jones under 633 nm illumination. The device shows ultra-fast response times of 4.5/4.9 μs, which is due to the introduction of 0D QDs will shorten the electron transport path and reduces trap-mediated non-radiative recombination. Further, the in-plane anisotropy of MAPbI3 QDs was identified by angle-resolved absorption spectroscopy and angle-resolved polarization Raman spectroscopy, respectively. The MAPbI3/WSe2 device exhibited polarization-sensitive optoelectronic detection with an anisotropy ratio of 1.71, and powerful polarization-sensitive imaging ability, implying that MAPbI3 QDs endows the device with polarization detection and imaging capabilities. These results indicate that the construction of 0D/2D MvdWH opens a new avenue for ultrasensitive and polarization-sensitive photodetection, which depicts opportunities for designing multifunctional, high-performance imaging optoelectronic devices.