Uncooled ultra-broadband infrared photodetectors based on core/shell/shell colloidal quantum dots

Abstract

Colloidal quantum dots (CQDs) have demonstrated unprecedented advantages in infrared (IR) photodetection due to their inexpensive chemical synthesis and solution processability. However, the lack of effective noise current suppression strategies severely hampers their highly sensitive IR sensing at room temperature, especially in the mid-wave infrared (MWIR) band. Here a dual type-II nano-heterostructure based on HgSe/PbSe/MAPbI₃ core/shell/shell (CSS) CQDs is designed to achieve an uncooled highly-sensitive ultra-broadband detection spanning form 330 nm-5300 nm. The CSS configuration not only creates dual electronic potential wells that efficiently suppress electrical noise but also forms a high-speed transport channel for photo-generated carrier collection. Consequently, the device operated at room temperature exhibits a blackbody detectivity of 1.1 ´ 10¹⁰ cm∙Hz^1/2/W and a MWIR peak detectivity of 2.6 ´ 10¹⁰ cm∙Hz^1/2/W at 3300 nm, which perform the best among the uncooled CQD photodetectors, and even rank among the top of state-of-the-art commercial uncooled IR detectors. This work opens up a new avenue for noise depression in CQD photodetectors and facilitates the development of uncooled, highly-sensitive, ultra-broadband IR photodetection.