A Colloidal‐Quantum‐Dot Infrared Photodiode with High Photoconductive Gain. Issue 48 (21st October 2018)

• Record Type: Journal Article
• Authors: 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
• Is Part Of: Small. Volume 14:Issue 48(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-21
• Subjects: colloidal quantum dots -- infrared photodiodes -- photoconductive gain; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201803158
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: 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. Abstract : A PbS colloidal‐quantum‐dot (CQD) photodiode has been fabricated, simultaneously achieving high responsivity, high external quantum efficiency, and fast response for 1550 nm photodetection. The great performance originates from the tetrabutylammonium iodide modification process that results in high carrier mobility, long carrier lifetime, and proper band structure in the CQDs. Combined with an ultrashort channel, the photodiode possesses high gain feature.