Study on the Mn-doped CsPbCl3 perovskite nanocrystals with controllable dual-color emission via energy transfer

Halide perovskite quantum dots (QDs) have been considered to be an outstanding optoelectronic material. However, the existence of Pb make it toxic, greatly hinders their practical application. Here, the Mn-doped is adopted to solve this problem without affecting their optical properties. Highly monodisperse low-Pb content Cs(Pb1-xMnx)Cl-3 (x = 0.3-0.7) perovskite QDs with cubic morphologies (similar to 7 nm edge lengths) are prepared though using the improved hot-injection method. The Mn-doped does not alter the crystal structure, and maintain the tetragonal crystalline structure of the CsPbCl3 host. The Cs(Pb1-xMnx)Cl-3 QDs exhibit two emissions, including the host emission similar to 400 nm and the Mn2+ emission similar to 590 nm. The PL intensity of 590 nm increase with the Mn increasing, attributing to the energy transfer of photoinduced excitons from the CsPbCl3 host to the doped Mn2+. Meanwhile, the positions of broad emission can be tuned by changing the Mn2+ content, indicating the emission color of samples can be controlled. Owing to the CsPbCl3 host -> Mn2+ energy transfer, the lifetimes for the CsPbCl3 host emission rapidly decreases. The temperature-dependent analysis has been performed, signature of the stimulated emission is observed at low temperature for excitation fluence. The emission intensity and position have been changed with the temperature rising, and the reason has been studied in detail. Meanwhile, the activation energy has been calculated, indicating that the Cs(Pb1-xMnx)Cl-3 QDs possesses good thermal stability. The low-Pb content perovskite quantum dots provides a novel platform for the application in optoelectronic device applications. (C) 2020 Elsevier B.V. All rights reserved.