Fabrication of CsPb1−xMnxBr3−2xCl2x (x = 0–0.5) quantum dots for near UV photodetector application

In this study, CsPb 1– x Mn x Br 3–2 x Cl 2 x ( x = 0–0.5) nanoparticles were synthesized directly in toluene solvents at high temperature. This approach results in small-size nanoparticles, which can be used in photoelectric components without adding a filtration process to eliminate high-temperature solvents such as octadecene. The high content Mn 2+ -incorporated CsPb(Cl/Br) 3 host is observed by strongly wideband emission at 592 nm of manganese d-states spin and orbital forbidden transition. After infiltration into mesoporous TiO 2 , the Mn 2+ ion receives energy from the CsPb(Cl/Br) 3 host (irradiated 405 nm light-emitting diode source) and effectively transfers to the TiO 2 scaffold layer. As a result, a metal/semiconductor/metal planar structure photodetector with m-TiO 2 /CsPb 1– x Mn x Br 3–2 x Cl 2 x ( x = 0–0.5) composite showed several figures of merit compared to bare m-TiO 2 and m-TiO 2 /CsPbBr 3 such as on/off ratio of 10 4 times, responsivity of 1.67 A·W −1 , and detectivity of 4.42 × 10 9 Jones. The key factors contributing to the growth of the on/off ratio include the decreasing dark current and enhancing exciton energy and transportation due to the infiltration of CsPb 1– x Mn x Br 3–2 x Cl 2 x ( x = 0–0.5) perovskite quantum dots into mesopores of the m-TiO 2 scaffold layer.