Passivated p-type silicon: Hole injection tunable anode material for organic light emission

Abstract

We find that hole injection can be enhanced simply by selecting a lower-resistivity p-Si anode to match an electron injection enhancement for organic light emitting diodes with ultrathin-SiO2-layer-passivated p-Si anode (Si-OLED). For a Si-OLED with ordinary AlQ electron transport layer, the optimized resistivity of the p-Si anode is 40Ωcm; for that with n-doped Bphen electron transport layer, it decreases to 5Ωcm. Correspondingly, the maximum power efficiency increases from 0.3to1.9lm∕W, even higher than that of an indium tin oxide control device (1.4lm∕W). This passivated p-type silicon is a hole injection tunable anode material for OLED.