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A Colloidal‐Quantum‐Dot Infrared Photodiode with High Photoconductive Gain
Author(s) -
Tang Yicheng,
Wu Feng,
Chen Fansheng,
Zhou Yi,
Wang Peng,
Long Mingsheng,
Zhou Wenjia,
Ning Zhijun,
He Jiawei,
Gong Fan,
Zhu Zhihong,
Qin Shiqiao,
Hu Weida
Publication year - 2018
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.201803158
Subject(s) - photodiode , responsivity , optoelectronics , materials science , photoconductivity , quantum efficiency , photodetection , quantum dot , dark current , diode , photodetector
The photodiode is a prevailing architecture for photodetection with the merits of fast response and low dark current. However, an ideal photodiode is also desired for both high responsivity and high external quantum efficiency (EQE), which may facilitate more applications. Here the photoconducting effect in a photodiode is discussed and an Au–PbS colloidal quantum dot (CQD)–indium tin oxide Schottky junction photodiode is fabricated. The long carrier lifetime and improved carrier mobility in tetrabutylammonium iodide–modified PbS CQDs cooperating with the proper band structure and an ultrashort channel in the diode enable the photodiode with high photoconductive gain, realizing an EQE of ≈400% and a responsivity ( R ) of 5.15 A W −1 while simultaneously achieving a response time of 110 µs and a specific detectivity of 1.96 × 10 10 Jones under 1550 nm illumination. In addition, this CQD‐based photodiode is stable, low cost, and compatible with complementary metal oxide semiconductor technology. All of these promise this device great potential in applications.