Compliant Substrate for Mid Infrared Wavelength Region
Abstract
The work in this project was focused on the growth of GaSb epilayer on a compliant layer by Molecular Beam Epitaxial (MBE) technique. A novel approach using the low temperature melting interlayer and a thin strained layer on top was investigated for compliancy. The structures examined consisted of GaAs host substrate, InSb as the low melting point interlayer, thin (Ga,Al) Sb layer, followed by thick GaSb overlayer. Growth results and characterization of these structures using various in-situ and ex-situ techniques are presented here. Amongst the different interlayers examined, InSb/GaSb(grown at low temperature of 400 deg C+) interlayer was found to be the most successful interlayer. The significant stress arising from the mismatch was accommodated by the interlayer, leading to reduced dislocation density (<10(exp 7)/sq cm) in the GaSb overlayer. Electronic properties of heteroepitaxial undoped and n-doping using SnTe source in InSb epilayers have been explained using the multichannel conduction process. High carrier (77K) mobility of 94,098 sq cm/V-sec on lightly doped samples has been achieved. Photoreflectance study of n-GaSb at E sub zero + delta sub zero transition energy has also been the subject of detailed investigation. The dependence of E sub zero + Delta sub zero transition energy on the doping levels has been analyzed by including the effects of band filling, band gap renormalization, and tail states.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 24, 2002
- Accession Number
- ADA408066
Entities
People
- Shanthi Iyer
Organizations
- North Carolina Agricultural and Technical State University