Zero-Dimensional PbS Quantum Dot-InGaZnO Film Heterostructure for Short-Wave Infrared Flat-Panel Imager

Hyun Tae Choi, Ji Hoon Kang, Jongtae Ahn, Junyoung Jin, Jaeyoung Kim, Soohyung Park, Yong Hoon Kim, Heedae Kim, Jin Dong Song, Gyu Weon Hwang, Seongil Im, Wooyoung Shim, Young Tack Lee, Min Chul Park, Do Kyung Hwang

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)


There is a growing demand for human-eye-invisible short-wave infrared (SWIR) detection due to its potential in applications in areas such as medical diagnostics, environmental monitoring, and night vision. PbS colloidal quantum dots (QDs) are a promising light absorber for SWIR detection. Herein, we report on a PbS QD/InGaZnO (IGZO) heterostructure-based phototransistor and flat-panel imager for human-eye-safe SWIR photodetection and high-resolution imaging. Such hybrid phototransistors show good electrical performance and obvious photoresponse behaviors with a maximum responsivity of 104 A/W and specific detectivity of 1012 Jones under 1310 nm SWIR illumination. We found that PbS QD ligand molecules significantly impact the environmental stability. Phototransistors featuring a tetrabutylammonium iodide (TBAI) ligand exhibit excellent air stability with no serious degradation after exposure to air for 3 weeks, while phototransistors with ethanedithiol (EDT) ligands lose their SWIR detecting capability within 2 weeks. Such an improved air stability may be correlated with the TBAI ligand passivation effect that is confirmed by X-ray photoemission spectroscopy analyses. PbS QDs are patterned on the flexible IGZO transistor array by photolithographic lift-off method for implementing a more practical imaging pixel array. Furthermore, we demonstrate a prototype of 1.3 μm SWIR flat-panel image sensor array, establishing its potential application in advanced developments as a gate-tunable, highly sensitive, high-resolution, and large area flat-panel SWIR imager.

Original languageEnglish
Pages (from-to)1932-1941
Number of pages10
JournalACS Photonics
Issue number8
Publication statusPublished - 2020 Aug 19

Bibliographical note

Publisher Copyright:
© 2020 American Chemical Society.

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


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