Competition of optical transitions between direct and indirect bandgaps in Ge1−xSnx
Abstract
Temperature-dependent photoluminescence (PL) study has been conducted in Ge1−xSnx films with Sn compositions of 0.9%, 3.2%, and 6.0% grown on Si. The competing between the direct and indirect bandgap transitions was clearly observed. The relative peak intensity of direct transition with respect to the indirect transition increases with an increase in temperature, indicating the direct transition dominates the PL at high temperature. Furthermore, as Sn composition increases, a progressive enhancement of direct transition was observed due to the reduction of direct-indirect valley separation, which experimentally confirms that the Ge1−xSnx could become the group IV-based direct bandgap material grown on Si by increasing the Sn content.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 04, 2014
- Source ID
- 10.1063/1.4892302
Entities
People
- Aboozar Mosleh
- Amjad Nazzal
- Benjamin R. Conley
- Greg Sun
- Hameed A. Naseem
- Joe Margetis
- John Tolle
- Richard Soref
- Seyed Amir Ghetmiri
- Shui-Qing Yu
- Wei Du
Organizations
- Air Force Office of Scientific Research
- Defense Advanced Research Projects Agency
- Experimental Program to Stimulate Competitive Research
- University of Arkansas
- University of Massachusetts Boston
- Wilkes University