Improved device efficiency and lifetime of perovskite light-emitting diodes by size-controlled polyvinylpyrrolidone-capped gold nanoparticles with dipole formation
Chang Min Lee, Dong Hyun Choi, Amjad Islam, Dong‐Hyun Kim, Tae Wook Kim, Geon‐Woo Jeong, Hyun Woo Cho, Min Jae Park, Syed Hamad Ullah Shah, Hyung Ju Chae, Kyoung‐Ho Kim, Muhammad Sujak, Jae Woo Lee, Donghyun Kim, Chul Hoon Kim, Hyun Jae Lee, Tae‐Sung Bae, Seung Min Yu, Jong Sung Jin, Yong‐Cheol Kang, Juyun Park, Myungkwan Song, Chang Su Kim, Sung Tae Shin, Seung Yoon Ryu, Sung Tae Shin, Seung Yoon Ryu
Abstract
Abstract Herein, an unprecedented report is presented on the incorporation of size-dependent gold nanoparticles (AuNPs) with polyvinylpyrrolidone (PVP) capping into a conventional hole transport layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The hole transport layer blocks ion-diffusion/migration in methylammonium-lead-bromide (MAPbBr 3 )-based perovskite light-emitting diodes (PeLEDs) as a modified interlayer. The PVP-capped 90 nm AuNP device exhibited a seven-fold increase in efficiency (1.5%) as compared to the device without AuNPs (0.22%), where the device lifetime was also improved by 17-fold. This advancement is ascribed to the far-field scattering of AuNPs, modified work function and carrier trapping/detrapping. The improvement in device lifetime is attributed to PVP-capping of AuNPs which prevents indium diffusion into the perovskite layer and surface ion migration into PEDOT:PSS through the formation of induced electric dipole. The results also indicate that using large AuNPs (> 90 nm) reduces exciton recombination because of the trapping of excess charge carriers due to the large surface area.