Interface Properties of Wide Bandgap Semiconductor Structures
Abstract
Exposure of selected areas of particular GaN samples with He-Cd laser light (3.8 eV) revealed a persistent and marked decrease in the near band edge photoluminescence (PL) intensity emitted from these areas. This ability to modulate PL emission intensity at individual points in these materials can be exploited as a method for optical data storage. A means of erasing information stored using this effect has also been investigated using lower energy (approx. 2 eV) photons. The microstructures and PL spectra were determined for Inx(2)Ga(1-x)N films (x less than or equal approx. 0.23) grown on substrates of a(6H)-SiC(0001) wafer/AlN buffer layer/GaN heterostructures by low pressure MOVPE at 780 deg C using nitrogen as the diluent and carrier gas and V/III ratios as low as 2,420. Indium droplets were not observed. The maximum InN content achievable at 45 Torr was approx. 13%. Increasing the deposition pressure to 90 Torr increased the maximum InN content to approx. 23%. Room temperature and 12K PL spectra of the films revealed single-feature, near band edge (NBE) emission with increasing full width at half maximum (FWHM) values with increasing infraction. The PL NBE FWHM for an In(0.23)Ga(0.77)N film at 12 K was 103 meV. InGaN films, 0.3 to 0.5 mm thick, in the 0-50% InN composition range have been analyzed by q-2q on, transmission electron microscopy and selected area diffraction for the occurrence of phase separation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1997
- Accession Number
- ADA340343
Entities
People
- J. Bernholc
- Robert F Davis
- Robert J. Nemanich
- Sarah S. Bedair
- Zlatko Sitar
Organizations
- North Carolina State University