Bandgap Tuning with Thermal Residual Stresses Induced in a Quantum Dot. Issue 18 (15th May 2014)

• Record Type: Journal Article
• Authors: Kong, Eui‐Hyun; Joo, Soo‐Hyun; Park, Hyun‐Jin; Song, Seungwoo; Chang, Yong‐June; Kim, Hyoung Seop; Jang, Hyun Myung
• Is Part Of: Small. Volume 10:Issue 18(2014:Sep.)
• Page Start: 3678
• Page End: 3684
• Publication Date: 2014-05-15
• Subjects: Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201400392
• Languages: English
• ISSNs: 1613-6810

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Lattice distortion induced by residual stresses can alter electronic and mechanical properties of materials significantly. 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 TiO₂ 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 coefficients between CdS and TiO₂. The idea of bandgap tuning is then applied to QD‐sensitized solar cells, achieving ≈60% increase in the power conversion efficiency by controlling the degree of thermal residual stress. Since the present methodology is not limited to a specific QD system, it will potentially pave a way to unexplored quantum effects in various QD‐based applications.</p> </abstract>