Ultrasensitive PbS quantum-dot-sensitized InGaZnO hybrid photoinverter for near-infrared detection and imaging with high photogain

Do Kyung Hwang, Young Tack Lee, Hee Sung Lee, Yun Jae Lee, Seyed Hossein Shokouh, Ji Hoon Kyhm, Junyeong Lee, Hong Hee Kim, Tae Hee Yoo, Seung Hee Nam, Dong Ick Son, Byeong Kwon Ju, Min Chul Park, Jin Dong Song, Won Kook Choi, Seongil Im

Research output: Contribution to journalArticlepeer-review

128 Citations (Scopus)


Lead sulfide (PbS) quantum dots (QDs) have great potential in optoelectronic applications because of their desirable characteristics as a light absorber for near-infrared (NIR) photodetection. However, most PbS-based NIR photodetectors are two-terminal devices, which require an integrated pixel circuit to be practical photosensors. Here we report on PbS QD/indium gallium zinc oxide (InGaZnO, IGZO) metal oxide semiconductor hybrid phototransistors with a photodetection capability between 700 and 1400 nm, a range that neither conventional Si nor InGaAs photodetectors can cover. The new hybrid phototransistor exhibits excellent photoresponsivity of over 106AW-1 and a specific detectivity in the order of 1013 Jones for NIR (1000 nm) light. Furthermore, we demonstrate an NIR (1300 nm) imager using photogating inverter pixels based on PbS/IGZO phototransistors at an imaging frequency of 1 Hz with a high output voltage photogain of ∼ 4.9 V (∼99%). To the best of our knowledge, this report demonstrates the first QD/metal oxide hybrid phototransistor-based flat panel NIR imager. Our hybrid approach using QD/metal oxide paves the way for the development of gate-tunable and highly sensitive flat panel NIR sensors/imagers that can be easily integrated.

Original languageEnglish
Article numbere233
JournalNPG Asia Materials
Issue number1
Publication statusPublished - 2016 Jan 8

Bibliographical note

Copyright 2017 Elsevier B.V., All rights reserved.

ASJC Scopus subject areas

  • Modelling and Simulation
  • General Materials Science
  • Condensed Matter Physics


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