Multiple exciton generation for photoelectrochemical hydrogen evolution reactions with quantum yields exceeding 100%

Yong Yan, Ryan W. Crisp, Jing Gu, Boris D. Chernomordik, Gregory F. Pach, Ashley R. Marshall, John A. Turner, Matthew C. Beard

Research output: Contribution to journalArticlepeer-review

108 Scopus citations

Abstract

Multiple exciton generation (MEG) in quantum dots (QDs) has the potential to greatly increase the power conversion efficiency in solar cells and in solar-fuel production. During the MEG process, two electron-hole pairs (excitons) are created from the absorption of one high-energy photon, bypassing hot-carrier cooling via phonon emission. Here we demonstrate that extra carriers produced via MEG can be used to drive a chemical reaction with quantum efficiency above 100%. We developed a lead sulfide (PbS) QD photoelectrochemical cell that is able to drive hydrogen evolution from aqueous Na 2 S solution with a peak external quantum efficiency exceeding 100%. QD photoelectrodes that were measured all demonstrated MEG when the incident photon energy was larger than 2.7 times the bandgap energy. Our results demonstrate a new direction in exploring high-efficiency approaches to solar fuels.

Original languageEnglish (US)
Article number17052
JournalNature Energy
Volume2
Issue number5
DOIs
StatePublished - Mar 27 2017

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Energy Engineering and Power Technology

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