Near‐Infrared and Visible‐Range Optoelectronics in 2D Hybrid Perovskite/Transition Metal Dichalcogenide Heterostructures

Abstract

The application of ultrathin 2D perovskites in near‐infrared and visible‐range optoelectronics is limited owing to their inherent wide bandgaps, large excitonic binding energies, and low optical absorption at higher wavelengths. Here, it is shown that by tailoring interfacial band alignments via conjugation with low‐dimensional materials like monolayer transition metal dichalcogenides (TMD), the functionalities of 2D perovskites can be extended to diverse, visible‐range photophysical applications. Based on the choice of individual constituents in the 2D perovskite/TMD heterostructures, first principles calculations demonstrate widely tunable type‐II bandgaps, carrier effective masses, and band offsets to enable an effective separation of photogenerated excitons for enhanced photodetection and photovoltaic applications. In addition, the possibilities of achieving a type‐I band alignment for recombination‐based light emitters as well as a type‐III configuration for tunneling devices are shown. Further, the effect of strain on the electronic properties of the heterostructures are evaluated to show a significant strain tolerance, making them prospective candidates in flexible photosensors.

BA2XBr4 (X = Pb, Cu, Sn): from lead to lead-free halide perovskite scintillators

“…We obtain calculated bandgaps ( E cal g ) of 3.36, 3.84, and 2.68 eV for BA 2 PbBr 4 , BA 2 CuBr 4 , and BA 2 SnBr 4 , respectively, the former of which agrees well with the previous theoretical study using the hybrid HSE06 functional (3.37 eV). 31 These similar E g values result in the similar estimated maximum light yields for all these crystals. The band structure of BA 2 CuBr 4 in Fig.…”

Recent advances of two-dimensional material additives in hybrid perovskite solar cells

“…The good chemical stability of 2D TMDs under moisture, light illumination, and heat also helps stabilize the perovskite active layer [74]. Being a semiconductor with band gap in visible range, TMDs can also improve the light interaction with hybrid perovskites through the formation of heterojunctions [75]. Below, we summarize a few key 2D TMD material systems used as additives for improving the performance and stability of PSCs (table 3).…”

All-inorganic lead halide perovskite nanocrystals applied in advanced display devices

“…94 Chemical vapor deposition (CVD) growth is one of the popular techniques to synthesize low-dimensional materials, where reaction sources are placed at the end of the tube. [95][96][97][98][99][100] All-inorganic CsPbX 3 microspheres with tunable sizes (0.2-10 mm) were successfully fabricated by dual-source CVD, as shown in Fig. 3b, and the trick of forming the spherical shape is constructing surface tension forces at high temperature.…”