Light-emitting field-effect transistors based on composite films of polyfluorene and CsPbBr$_{3}$ nanocrystals

Light-emitting organic field-effect transistors (LE-FETs) on the basis of composite films that consist of perovskite nanocrystals (CsPbBr$_{3}$) embedded in a matrix of conjugated polymer–polyfluorene (PFO)–have been obtained, and their electrical and optical properties have been investigated. Output and transfer current-voltage characteristics (I-Vs) of FETs based on PFO : CsPbBr$_{3}$ films (component ratio 1 : 1) have a slight hysteresis at temperatures of 100–300 K and are characteristic of hole transport. The hole mobility is $\sim$3.3 and $\sim$1.9 cm$^2$/(V s) at the modes of the saturation and low fields, respectively, at 250 K and reaches $\sim$5 cm$^2$/(V s) at 100 K. It has been shown that the application of pulsed voltage to LE-FETs based on PFO:CsPbBr$_{3}$ can reduce the ionic conductivity and provide electroluminescence in this structure at 300 K.