Room-Temperature-Operated Ultrasensitive Broadband Photodetectors by Perovskite Incorporated with Conjugated Polymer and Single-Wall Carbon Nanotubes

摘要

In this work, room-temperature-operated ultrasensitive solution-processed perovskite photodetectors (PDs) with near infrared (NIR) photoresponse are reported. In order to enable perovskite PDs possessing extended NIR photoresponse, novel n-type low bandgap conjugated polymer, poly[(N, N'bis(2-octyldodecyl)-1,4,5,8-naphthalene diimide-2,6-diyl) (2,5-dioctyl-3,6-di(thiophen-2-yl) pyrrolo[3,4-c] pyrrole-1,4-dione-5,5'-diyl)] (NDI-DPP), which has strong absorption in the NIR region, is developed and then employed in perovskite PDs. By the formation of type II band alignment between NDI-DPP with single-wall carbon nanotubes (SWCNTs), the NIR absorption of NDI-DPP is exploited, which contributes to the NIR photoresponse for the perovskite PDs, where perovskite is incorporated with NDI-DPP and SWCNTs as well. In addition, SWCNTs incorporated with perovskite active layer can offer the percolation pathways for high charge-carrier mobility, which tremendously boosts the charge transfer in the photoactive layer, and consequently improves the photocurrent in the visible region. As a result, the perovskite PDs exhibit the responsivities of approximate to 400 and approximate to 150 mA W-1 and the detectivities of over 6 x 10(12) Jones (1 Jones = 1 cm Hz(1/2) W-1) and over 2 x 10(12) Jones in the visible and NIR regions, respectively. This work reports the development of perovskite PDs with NIR photoresponse, which is terrifically beneficial for the practical applications of perovskite PDs.