Sequential Co-Passivation in InAs Colloidal Quantum Dot Solids Enables Efficient Near-Infrared Photodetectors

Pan Xia, Bin Sun, Margherita Biondi, Jian Xu, Ozan Atan, Muhammad Imran, Yasser Hassan, Yanjiang Liu, Joao M. Pina, Amin Morteza Najarian, Luke Grater, Koen Bertens, Laxmi Kishore Sagar, Husna Anwar, Min Jae Choi, Yangning Zhang, Minhal Hasham, F. Pelayo García de Arquer, Sjoerd Hoogland, Mark W.B. WilsonEdward H. Sargent

Research output: Contribution to journalArticlepeer-review

30 Scopus citations

Abstract

III-V colloidal quantum dots (CQDs) are promising materials for optoelectronic applications, for they avoid heavy metals while achieving absorption spanning the visible to the infrared (IR). However, the covalent nature of III-V CQDs requires the development of new passivation strategies to fabricate conductive CQD solids for optoelectronics: this work shows herein that ligand exchanges, previously developed in II-VI and IV-VI quantum dots and employing a single ligand, do not fully passivate CQDs, and that this curtails device efficiency. Guided by density functional theory (DFT) simulations, this work develops a co-passivation strategy to fabricate indium arsenide CQD photodetectors, an approach that employs the combination of X-type methyl ammonium acetate (MaAc) and Z-type ligands InBr3. This approach maintains charge carrier mobility and improves passivation, seen in a 25% decrease in Stokes shift, a fourfold reduction in the rate of first-exciton absorption linewidth broadening over time-under-stress, and leads to a doubling in photoluminescence (PL) lifetime. The resulting devices show 37% external quantum efficiency (EQE) at 950 nm, the highest value reported for InAs CQD photodetectors.

Original languageEnglish
Article number2301842
JournalAdvanced Materials
Volume35
Issue number28
DOIs
StatePublished - 13 Jul 2023

Keywords

  • III-V compound semiconductors
  • indium arsenide
  • near-infrared photodetectors

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