High-Performance van der Waals Photodetectors Based on 2D Ruddlesden–Popper Perovskite/MoS₂ Heterojunctions

Abstract

Perovskites have prevailed in the field of photovoltaics over the past several years thanks to their outstanding optoelectronic properties. Compared to threedimensional (3D) perovskites, the emerging two-dimensional (2D) Ruddlesden− Popper (RP) phase perovskites have demonstrated superior stability due to their hydrophobic organic capping ligands, which can protect the inside inorganic octahedrons against moisture. Meanwhile, RP perovskites broaden the family of 2D materials, enriching the building blocks for van der Waals heterostructures. Here, we first demonstrated a vertical heterojunction incorporating RP perovskite (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 and MoS 2 . The heterojunction photodetector exhibits an extremely low dark current down to 0.1 pA, which can be attributed to the combining effect of the low carrier density in RP perovskites and the band structure of the heterojunction. The spatially resolved scanning photocurrent microscopy (SPCM) was carried out to confirm the charge transport mechanism and band alignment of the heterojunction. Moreover, the photodetector benefits from the heterojunction structure, leading to a high photoresponsivity (7.98 mA W −1 ). In addition, the device can be operated under a self-driven mode with a responsivity of 0.168 mA W −1 . Our work proves the compatibility of RP perovskites in van der Waals devices, promising a scalable pathway to further applications.

Spin Texture Sensitive Photodetection by Dion–Jacobson Tin Halide Perovskites

“…The 4N4-Br/I devices prevail over all its counterparts (Figure S32), and its R value of 78.1 A W –1 at 3 V clearly outperforms those from all the previously reported DJ perovskite photoabsorbers, − ,− and most of the RP perovskite devices, − except those in the form of single crystals, heterostructures with MoS 2 , under higher potential or lower intensity laser light (Table S17). − In spite of having the insulating organic spacer, 4N4-Br/I also shows comparable responsivity with respect to the 3D lead-based perovskites, − except a few CsPbX 3 (X = Br/I) microcrystals or films (Table S18).…”

“… − The same holds true for the 4N4-Br/I self-powered devices where its R (0.085 A W –1 ) and D (9.9 × 10 10 jones) surpass the earlier reports on DJ perovskite photodetectors under zero bias, − albeit having comparable results with a few RP perovskite self-powered photodetectors (Table S20). ,, Under the self-powered condition, the champion 4N4-Br/I photodetectors exhibit comparable to or slightly lower R values than the reported bulk 3D systems (Table S21). − On a brighter note, the D values are of the same order of magnitude (∼10 11 ) as most of the 3D perovskites at 0 V. Our experimental results showcase ample room for innovations among the lead-free 2D perovskite family in order to outperform the photodetector performances of 3D perovskites and lead-based 2D perovskites.…”

Recent advances in 2D transition metal dichalcogenide-based photodetectors: a review

“…The photoresponse of the PEAPBr/ MoS 2 heterojunction PD was enhanced through a meticulous study and exhibited the tremendous potential of the photovoltaic devices fabricated using RP perovskites and 2D materials. 96 The 2D perovskites have been widely investigated as tremendous light-sensitive materials in the field of optoelectronics due to their enhanced structural stability over their 3D counterparts. Moreover, the utilization of 2D perovskitebased PDs in the NIR region is prevented through a wide intrinsic optical band gap.…”

“…The photoresponse of the PEAPBr/MoS 2 heterojunction PD was enhanced through a meticulous study and exhibited the tremendous potential of the photovoltaic devices fabricated using RP perovskites and 2D materials. 96…”

Recent advances in enhancing the photodetector performance of 2D materials by combining them with organic thin films

“…2D Ruddlesden–Popper (RP) phase perovskites exhibit excellent stability, and (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 /MoS 2 proposed by Xu et al (Fig. 14g–i) 188 demonstrates an ultra-low dark current (0.1 pA), owing to the low carrier density of (C 6 H 5 C 2 H 4 NH 3 ) 2 PbBr 4 and the reasonable band structure of the heterojunction. Furthermore, this device maintains excellent photodetection performance after over a thousand switching cycles.…”