Ultimate Charge Extraction of Monolayer PbS Quantum Dot for Observation of Multiple Exciton Generation

So Yeon Park, Sehoon Han, Younghoon Kim, Sohee Jung, Dong Hoe Kim, Gill Sang Han, Hyun Suk Jung

Research output: Contribution to journalArticlepeer-review

Abstract

Multiple exciton generation (MEG) has great potential to improve the Shockley-Queisser (S-Q) efficiency limitation for colloidal quantum dot (CQD) solar cells. However, MEG has rarely been observed in CQD solar cells because of the loss of carriers through the transport mechanism between adjacent QDs. Herein, we demonstrate that excess charge carriers produced via MEG can be efficiently extracted using monolayer PbS QDs. The monolayer PbS QDs solar cells exhibit α=1 in the light intensity dependence of the short-circuit current density Jsc (Jsc∝Iα) and an internal quantum efficiency (IQE) value of 100 % at 2.95 eV because of their very short charge extraction path. In addition, the measured MEG threshold is 2.23 times the bandgap energy (Eg), which is the lowest value in PbS QD solar cells. We believe that this approach can provide a simple method to find suitable CQD materials and design interface engineering for MEG.

Original languageEnglish
Pages (from-to)2657-2661
Number of pages5
JournalChemPhysChem
Volume20
Issue number20
DOIs
Publication statusPublished - 2019 Oct 16
Externally publishedYes

Keywords

  • colloid quantum dot solar cell
  • fast charge extraction
  • Langmuir–Blodgett
  • monolayer PbS
  • multiple exciton generation

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Ultimate Charge Extraction of Monolayer PbS Quantum Dot for Observation of Multiple Exciton Generation'. Together they form a unique fingerprint.

Cite this