High‐Performance and Stability of CsPbBr₃/WSe₂ Hybrid Photodetectors Functionalized Using Quaternary Ammonium Ligands

Abstract

The 2D–0D hybrid photodetector, with its special structure, high sensitivity, and wavelength tunability, is reported as a promising candidate system for optoelectronic devices. As research on hybrid lead halide perovskite quantum dots (PQDs) has progressed, PQDs with high photoluminescence (PL) quantum yield and excellent absorption properties are increasingly applied in optoelectronic devices; however, PQD stability remains one of the biggest limitations on device performance. Here, it is reported that the properties and stability of the hybrid photodetectors are improved by surface passivation using the quaternary ammonium ligand (didodecyldimethylammonium bromide, DDAB). The average carrier lifetime of DDAB treated CsPbBr3 PQDs (DDAB‐capped PQDs) is longer than that of pristine CsPbBr3 PQDs by 6.68–14.88 ns. It is confirmed that the durability against water is reduced by only 25.8% at PL intensity and is preserved for more than 16 h. A 2D–0D hybrid photodetector is then fabricated by deposition of DDAB‐capped PQDs on the WSe2 field‐effect transistor device for a high‐performance photodetector. The WSe2/DDAB‐capped PQD hybrid photodetector exhibits an enhanced responsivity of 1.4 × 103 A W−1 and an improved detectivity of 3.1 × 1013 Jones under 40.0 µW cm−2 of a 405 nm laser.

Colloidal quantum dots and two‐dimensional material heterostructures for photodetector applications

“…164,165 The colloidal stability of the PQDs could also decrease as a result of the bonding of labile ligands to the surface atoms of PQDs, which gives rise to surface trap sites. 166 Therefore, in order to solve these urgent issues, Moon et al 167 recently proposed a surface passivation strategy to improve the stability of CrPbBr 3 PQDs while optimizing optical properties. The quaternary ammonium ligand (didodecyldimethylammonium bromide, DDAB) was employed to inhibit the proton transfer between OLA and OA, thereby effectively passivating the surface of CrPbBr 3 PQDs.…”

4-Chlorrate Assisted in Situ Passivation of CsPbCl3 Perovskite Quantum Dots with High Water Stability for Light-Emitting Diode

“…For example, Moon et al reported a surface passivation strategy using quaternary ammonium ligands (docosenyl dimethylammonium bromide, DDAB) to improve the performance and stability of CsPbBr 3 •PQDs. 30 Unfortunately, the surface-modified CsPbBr 3 •PQDs water stability test was conducted for only 16 h, and it cannot be demonstrated that it has long-term water stability that can improve practical applications. A large improvement in water stability can usually be obtained by using the coating method.…”

“…Similarly, this method has limited stability improvement for QDs in water, and relatively few reports have been reported. For example, Moon et al reported a surface passivation strategy using quaternary ammonium ligands (docosenyl dimethylammonium bromide, DDAB) to improve the performance and stability of CsPbBr 3 ·PQDs . Unfortunately, the surface-modified CsPbBr 3 ·PQDs water stability test was conducted for only 16 h, and it cannot be demonstrated that it has long-term water stability that can improve practical applications.…”

Emerging Schemes for Advancing 2D Material Photoconductive-Type Photodetectors

“…Proof-of-concept double-sided imaging has been realized based on two kinds of electronic eye prototypes (concave and convex hemispheres) in a single device configuration. Thus far, researchers have developed numerous photodetectors based on various 2DLMs spanning elemental semiconductors/semimetals [68][69][70][71][72], chalcogenides [73][74][75][76][77][78][79][80][81][82][83], nitrides [84], multi-elemental semiconductors [85][86][87][88][89][90][91][92], etc.…”