On-Demand Stoichiometry Control of Copper Sulfide Nanocrystals with Omni-Tunable Semiconductor Properties
Abstract
Copper sulfide nanocrystals (NC) show unique electric/optoelectronic properties rooted from the stoichiometric mismatch between copper and sulfur atoms. A small number of copper is driven thermodynamically to escape from the lattice of the crystalline structure, and NCs with copper deficiencies, i.e. Cu2-xS NCs (where x represents the degree of mismatched stoichiometry) are formed. Because each copper deficient site serves as an acceptor to the semiconductor, Cu2-xS NCs yields self-doped p-type electrical properties determined by x. In this project, we plan to develop a versatile conversion platform that allows on-demand control of the carrier density for Cu2-xS NCs. This platform will be established by means of electrochemical method utilizing the assemblies of Cu2-xS NCs as the working electrode of an electrochemical cell. The degree of the oxidation/reduction for Cu2-xS NCs will be accurately controlled by electric potential applied to the electrode. The resulting variation of the stoichiometry will be determined through an in situ spectroelectrochemical technique that monitors the LSPR of the material at corresponding potentials. Using the platform, we plan to investigate the fundamental characteristics of the Cu2-xS NCs films including their electrical, thermoelectric, and optical properties. The fundamental understanding from the study will provide practical guidelines for developing advanced electronic devices for military purpose.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 19, 2018
- Source ID
- FA23861814008
Entities
People
- Wansoo Huh
Organizations
- Air Force Office of Scientific Research
- Soongsil University
- United States Air Force