Improved efficiency of red perovskite quantum dots-based light-emitting diodes by thickness tuning of PEDOT:PSS

To balance the carrier injection, adjusting the thickness of PEDOT:PSS through a simple water diluting was a feasible strategy to improve the efficiency of CsPbBrI 2 perovskite quantum dots light-emitting diode (PeLED). CsPbBrI 2 perovskite quantum dots (PeQDs) with a uniform and monodisperse cubic phase exhibited a red light at 649 nm and with CIE of (0.697, 0.302). Based on PEDOT:PSS film with the thickness of 40 nm, a CsPbBrI 2 PeLED displayed 4.3-fold external quantum efficiency improvement up to 3.44%, and 22.3-fold enhancement in luminance, which was attributed to an effective hole transport and an increased electrical conductivity.