Rational Energy Band Alignment and Au Nanoparticles in Surface Plasmon Enhanced Si-Based Perovskite Quantum Dot Light-Emitting Diodes

摘要

Combining inorganic perovskite quantum dots (IPQDs) devices withrnSi platform is an interesting topic since it is helpful for realizing thernoptoelectronic integration as well as the multiple-functional electronicsrnin a compact and lightweight format. However, the poor energy bandrnalignment between the IPQDs and Si limits the device performance, suchrnas the emitting efficiency. Here, a light-emitting diodes (LEDs) structurernis proposed by inserting a poly-TPD (poly[N,N′-bis(4-butylphenyl)-N,N′-rnbis(phenyl)-benzidine]) layer between the n-type IPQDs and the p-type Sirnsubstrate. The light-emitting diode based on CsPbI_3 quantum dots reachesrnan output power density of 1.68 mW cm~(−2) with external quantum efficiencyrnof 0.91%, which is enhanced by 34-fold compared with the referencerndevice. Similar emission enhancement is also observed in the device basedrnon CsPbBr_3 quantum dots but the output power density is onlyrn0.6 mW cm~(−2). In order to further improve the emission intensity ofrnCsPbBr3 quantum dots devices, Au nanoparticals (Au NPs) are introducedrninto the hole injection layer, the output power density increases torn1.2 mW cm~(−2), which is induced by the localized surface plasmon resonancerncoupling between Au NPs and CsPbBr_3 excitons. The results demonstraternthat high-efficiency and stable Si-based perovskite LEDs can be realized byrnrational optical and electronic design.