Growth and Characterization of GaN As(P) for High Efficiency Solar Cells: Final Subcontract Report, 29 July 1999--28 September 2003

Technical Report · Tue Jun 01 00:00:00 EDT 2004

DOI:https://doi.org/10.2172/15007877· OSTI ID:15007877

Narayanamurti, V

This report describes the characterization of GaAs1-xNx and GaP1-xNx alloys using scanning tunneling microscopy (STM) and ballistic electron emission microscopy (BEEM). One objective was to understand the origins of the giant bandgap bowing of these compound semiconductor alloys as a function of nitrogen concentration. The STM and BEEM have been used to characterize GaNxAs1-x and GaNxP1-x as a function of composition. The reduction in bandgap has been measured. Detailed studies of the band structure as a function of N composition has led to a basic understanding of the materials system. The major results of this work include: (i) determination of relative contributions of the G- and L-like bands of GaNxAs1-x to the BEEM spectra; (ii) determination of the composition dependence of the Au/ G- and L-like bands of GaNxAs1-x Schottky barrier height; (iii) development of a model to describe the BEEM results at nonepitaxial metal/semiconductor interfaces; and (iv) ballistic electron emission spectroscopy studies of GaNxP1-x samples that demonstrated possible splitting in the degeneracy of the X valley due to the nitrogen. The data were qualitatively described by the recent perturbed host states model of Kent and Zunger.

• Research Organization: National Renewable Energy Lab., Golden, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99GO10337
• OSTI ID: 15007877
• Report Number(s): NREL/SR-520-36318; AAD-9-18668-17
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
47 OTHER INSTRUMENTATION
ALLOYS
BALLISTIC ELECTRON EMISSION MICROSCOPY (BEEM)
BANDGAP
EFFICIENCY
ELECTRON EMISSION
MICROSCOPY
NITROGEN
PV
SCANNING TUNNELING MICROSCOPY
SCANNING TUNNELING MICROSCOPY (STM)
SCHOTTKY BARRIER
SEMICONDUCTOR ALLOYS
SOLAR CELLS
SOLAR ENERGY
SOLAR ENERGY - PHOTOVOLTAICS
SPECTRA
SPECTROSCOPY