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High‐Speed Colloidal Quantum Dot Photodiodes via Accelerating Charge Separation at Metal–Oxide Interface
Author(s) -
Jeong ShinYoung,
Kyhm Jihoon,
Cha SoonKyu,
Hwang Do Kyung,
Ju ByeongKwon,
Park JoonSuh,
Kang Seong Jun,
Han Il Ki
Publication year - 2019
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201900008
Subject(s) - photodiode , quantum dot , materials science , photodetector , optoelectronics , interface (matter) , oxide , resolution (logic) , image sensor , nanotechnology , optics , physics , computer science , contact angle , sessile drop technique , artificial intelligence , metallurgy , composite material
With ever‐growing technological demands in the imaging sensor industry for autonomous driving and augmented reality, developing sensors that can satisfy not only image resolution but also the response speed becomes more challenging. Herein, the focus is on developing a high‐speed photosensor capable of obtaining high‐resolution, high‐speed imaging with colloidal quantum dots (QDs) as the photosensitive material. In detail, high‐speed QD photodiodes are demonstrated with rising and falling times of τ r = 28.8 ± 8.34 ns and τ f = 40 ± 9.81 ns, respectively, realized by fast separation of electron–hole pairs due to the action of internal electric field at the QD interface, mainly by the interaction between metal oxide and the QD's ligands. Such energy transfer relations are analyzed and interpreted with time‐resolved photoluminescence measurements, providing physical understanding of the device and working principles.