Preliminary Investigation into the Effect of High Temperature Thermal Anneals on the Figure of Merit of Silicon Germanium Alloys
Abstract
In this report is embodied the results of a preliminary theoretical and experimental investigation into the effect of high temperature thermal anneals on the thermoelectric figure of merit of silicon germanium-gallium phosphide material. A realistic theoretical model for the silicon germanium alloy system is employed to investigate the effect of an increase in the doping level on the electrical power factor alpha square (sigma) where alpha is the Seebeck coefficient and sigma the electrical conductivity. The assumption is made that the addition of gallium phosphide to silicon germanium alloy serves only to increase the dopant solubility and hence the carrier concentration. The theoretical analysis indicates that the reported factor of 1.6 increase in the carrier concentration of heat treated silicon germanium-gallium phosphide material compared to conventional silicon germanium alloy would result in an increase in the electrical power factor of between 12-14% at room temperature rising to 18-22% at 1000K. The results of this programme of work support the conclusion that the electrical power factor and hence the figure of merit of silicon germanium-gallium phosphide can be significantly improved by high temperature thermal anneals. Keywords: Transport properties, Semiconductors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1990
- Accession Number
- ADA218573
Entities
People
- D. M. Rowe
Organizations
- Cardiff University