Strong Photocurrent from Solution‐Processed Ruddlesden–Popper 2D Perovskite–MoS₂ Hybrid Heterojunctions

Abstract

Abstract This study reports overall improvement in structural, morphological, and optoelectronic properties of Ruddlesden–Popper (RP) perovskites of type (BA) 2 (MA) n −1 Pb n I 3 n +1 by forming their bulk heterojunction hybrids with few‐layer MoS 2 nanoflakes. RP perovskite–MoS 2 hybrid thin films have shown significantly improved packing and crystallinity compared to pristine perovskites. The presence of MoS 2 at RP perovskite interface has improved the quantum confinement effects and transport of photogenerated charge carriers from perovskite to MoS 2 , due to suitable conduction band of MoS 2 and more number of decay channels. The optoelectronic properties of RP perovskite–MoS 2 hybrids are studied for various MoS 2 concentrations (4.2–25.6 × 10 −3 m ) and at optimum concentration (12.8 × 10 −3 m ) the photodetectors ( n = 2, 4) have shown strong, sharp, and highly stable photocurrent response. At 0.0 V bias, the RP perovskite ( n = 4) and MoS 2 (12.8 × 10 −3 m ) hybrid‐based photodetectors, prepared without any encapsulation, have shown strong photocurrent density of ≈9.8 µA cm −2 under 1 sun illumination, which is ≈17 times higher compared to the pristine RP perovskites‐based photodetector (0.6 µA cm −2 ). Further transient photocurrent, performed over 200 cycles for hybrid ( n = 4+MoS 2 ) thin film photodetector under laser (λ ex ≈ 405 nm, ≈630 mW cm −2 ) illumination and ambient air conditions has shown highly stable photocurrent with only ≈9.6% reduction in the peak photocurrent density.