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Jung BK, Park T, Choi YK, Lee YM, Kim TH, Seo B, Oh S, Shim JW, Lo YH, Ng TN, Oh SJ. An ultra-sensitive colloidal quantum dot infrared photodiode exceeding 100 000% external quantum efficiency via photomultiplication. NANOSCALE HORIZONS 2024; 9:487-494. [PMID: 38260954 DOI: 10.1039/d3nh00456b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
In this study, we present ultrasensitive infrared photodiodes based on PbS colloidal quantum dots (CQDs) using a double photomultiplication strategy that utilizes the accumulation of both electron and hole carriers. While electron accumulation was induced by ZnO trap states that were created by treatment in a humid atmosphere, hole accumulation was achieved using a long-chain ligand that increased the barrier to hole collection. Interestingly, we obtained the highest responsivity in photo-multiplicative devices with the long ligands, which contradicts the conventional belief that shorter ligands are more effective for optoelectronic devices. Using these two charge accumulation effects, we achieved an ultrasensitive detector with a responsivity above 7.84 × 102 A W-1 and an external quantum efficiency above 105% in the infrared region. We believe that the photomultiplication effect has great potential for surveillance systems, bioimaging, remote sensing, and quantum communication.
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Affiliation(s)
- Byung Ku Jung
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
| | - Taesung Park
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
| | - Young Kyun Choi
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
| | - Yong Min Lee
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
| | - Tae Hyuk Kim
- School of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Bogyeom Seo
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093-0407, USA
| | - Seongkeun Oh
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
| | - Jae Won Shim
- School of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Yu-Hwa Lo
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093-0407, USA
| | - Tse Nga Ng
- Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, California 92093-0407, USA
| | - Soong Ju Oh
- Department of Materials Science and Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
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