Hole injection in perovskite light-emitting device with PEDOT:PSS/perovskite interface via MS contact

The hole-injection mechanism of FAPbBr3-based lead halide perovskite light-emitting diodes with PEDOT:PSS as the hole injection layer is revealed as the metal-semiconductor contact at the PEDOT:PSS/perovskite interface. The accumulation of ionic charges at the interface at the external voltage is responsible for the enhancement of hole injection. It is discovered that the strong binding between the positively charged PEDOT chain and the negatively charged Br− gives rise to the slowest charge relaxation. Moreover, the charge concentration of FAPbBr3 perovskite is estimated to be around 3.0 × 1018 cm−3 by saturating the relaxation current.