Dopant concentration-induced carrier conduction dynamics in manganese-doped perovskite quantum dots

Abstract

Achieving optimal performance in any optoelectronic device requires precise control of charge carrier generation and their efficient transport with minimal energy losses. In this Letter, we study the dependence of luminescence properties and interfacial charge transfer (CT) kinetics on Mn2+-doped CsPb(Br/Cl)3 perovskite quantum dots (PQDs) with varying dopant concentrations. Increased dopant content leads to an efficient CT with p-benzoquinone (BQ), as demonstrated by the spectroscopic analysis and energy band alignment. The electrical and electrochemical measurements further reveal an improved conductance and reduced resistance across the sample–electrode interface for higher-doped samples. The alteration in the dopant concentration not only influences the energy transfer to the dopants but also tempers the degree of current conduction through the perovskites. The presence of BQ again modulates the optoelectronic properties of the Mn2+-doped samples and also changes the nature of tunneling from a combined direct and Fowler–Northeim type to only direct tunneling across the junction interface. These findings decipher that regulated carrier transfer and transport in anion-exchanged PQDs can be structured with doping, making them promising candidates for highly efficient optoelectronic device applications.