Optimized TFB-based perovskite quantum dot light emitting diode

Abstract

Perovskite quantum dots (PQDs) are semiconducting nanocrystals that have been exploited for fabricating light-emitting diodes because of their exciton confinement, high quantum yield, and adjustable color. Therefore, PQD-based Light-emitting diodes (PQDLEDs) have attracted huge attention because of their significant external quantum efficiencies. In our research, to prohibit fluorescence quenching dots which is caused by the connection of the PQDs and hole injection material into the emissive layer and hole injection layer, poly [(9,9- dioctylfluorenyl-2,7-diyl)-co-(4,4’-(N-(pbutylphenyl)) diphenylamine)] (TFB) is utilized which can decrease the hole injection barrier. To reach the TFB's optimal thickness, we control both the precursor solution concentration and the rotational speed during the spin coating process. Finally, we find out that the optimal TFB precursor solution concentration and rotational speed are 8.0 mg ml−1, and 4500 rpm, respectively, which results in 35 nm thickness. The optimized PQDLED turn-on voltage, maximum brightness, maximum external quantum efficiency (EQE) (vs luminance), and maximum current efficiency were 2.2 V, 4522 cd m−2, ∼0.15%, and ∼0.5 cd A−1, respectively.