Bandgap tuning with thermal residual stresses induced in a quantum dot

Eui Hyun Kong, Soo Hyun Joo, Hyun Jin Park, Seungwoo Song, Yong June Chang, Hyoung Seop Kim, Hyun Myung Jang

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)

Abstract

Lattice distortion induced by residual stresses can alter electronic and mechanical properties of materials signifi cantly. Herein. A novel way of the bandgap tuning in a quantum dot (QD) by lattice distortion is presented using 4-nm-sized CdS QDs grown on a TiO 2 particle as an application example. The bandgap tuning (from 2.74 eV to 2.49 eV) of a CdS QD is achieved by suitably adjusting the degree of lattice distortion in a QD via the tensile residual stresses which arise from the difference in thermal expansion coeffi cients between CdS and TiO 2. The idea of bandgap tuning is then applied to QD-sensitized solar cells, achieving ∼60% increase in the power conversion effi ciency by controlling the degree of thermal residual stress. Since the present methodology is not limited to a specifi c QD system, it will potentially pave a way to unexplored quantum effects in various QD-based applications.

Original languageEnglish
Pages (from-to)3678-3684
Number of pages7
JournalSmall
Volume10
Issue number18
DOIs
Publication statusPublished - 2014 Sep 1
Externally publishedYes

ASJC Scopus subject areas

  • Biotechnology
  • Biomaterials
  • Chemistry(all)
  • Materials Science(all)

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