Improved Facet and Edge Passivation in Near‐Infrared III‐V Colloidal Quantum Dot Photodetectors
Abstract
Abstract Lead‐free III‐V colloidal quantum dots (CQDs) are of significant interest for their potential in near‐infrared (NIR) to short‐wave infrared (SWIR) photodetection. However, achieving effective surface passivation remains challenging, especially as larger CQD sizes introduce more complex surface facets and compositions while shifting the absorption peak from the NIR to the SWIR range. In this study, a mixed‐halide passivation strategy is developed for large InAs CQDs, an approach that led to a doubling in anti‐oxidation ability and achieves a hole mobility of 0.03 cm 2 Vs −1 . These in turn led to a T90 lifetime of 50 h and enhanced operating stability in photodetectors operating at 1140 nm. Density functional theory (DFT) simulations and facet characterization indicate that exposed facets and edges are well passivated using a mixture of indium halides, which provide a stronger desorption energy compared to single‐halide passivation. This approach yields photodetectors with an external quantum efficiency (EQE) of 75% and a response time of 10 ns, an advance for InAs photodetectors operating at 1140 nm.
Article Details
Authors (13)
Pan Xia
Sasa Wang
College of Electronic and Optical Engineering & College of Flexible Electronics (Future Technology) Nanjing University of Posts and Telecommunications 9 Wenyuan Road Nanjing 210023 China
Yiqing Chen
Department of Chemistry
Ahmet Gulsaran
Waterloo Institute for Nanotechnology, Department of Mechanical and Mechatronics Engineering University of Waterloo 200 University Ave W Waterloo Ontario N2L 3G1 Canada
Yangning Zhang
School of Biomedical Sciences and Engineering, Guangzhou International Campus
Maral Vafaie
Department of Mechanical and Industrial Engineering
Muhammad Imran
Amin Morteza Najarian
Department of Electrical and Computer Engineering
Yanjiang Liu
Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
Hyeongwoo Ban
Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
Laxmi Kishore Sagar
Department of Electrical and Computer Engineering University of Toronto 10 King's College Road Toronto Ontario M5S 3G4 Canada
Mustafa Yavuz
Waterloo Institute for Nanotechnology, Department of Mechanical and Mechatronics Engineering University of Waterloo 200 University Ave W Waterloo Ontario N2L 3G1 Canada
Edward H. Sargent