GaInNAs Structures Grown by MBE for High-Efficiency Solar Cells: Final Report; 25 June 1999--24 August 2002

Technical Report · Fri Aug 01 00:00:00 EDT 2003

DOI:https://doi.org/10.2172/15004566· OSTI ID:15004566

Tu, C W

The focus of this work is to improve the quality of GaInNAs by advanced thin-film growth techniques, such as digital-alloy growth techniques and migration-enhanced epitaxy (MEE). The other focus is to further investigate the properties of such materials, which are potentially beneficial for high-efficiency, multijunction solar cells. 400-nm-thick strain-compensated Ga0.92In0.08As/GaN0.03As0.97 short-period superlattices (SPSLs) are grown lattice-matched to GaAs substrates. The photoluminescence (PL) intensity of digital alloys is 3 times higher than that of random alloys at room temperature, and the improvement is even greater at low temperature, by a factor of about 12. The room-temperature PL intensity of the GaInNAs quantum well grown by the strained InAs/GaN0.023As SPSL growth mode is higher by a factor 5 as compare to the continuous growth mode. The SPSL growth method allows for independent adjustment of the In-to-Ga ratio without group III competition. MEE reduces the low-energy tail of PL, and PL peaks become more intense and sharper. The twin peaks photoluminescence of GaNAs grown on GaAs was observed at room temperature. The peaks splitting increase with increase in nitrogen alloy content. The strain-induced splitting of light-hole and heavy-hole bands of tensile-strained GaNAs is proposed as an explanation of such behavior.

• Research Organization: National Renewable Energy Lab. (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-99-GO10337
• OSTI ID: 15004566
• Report Number(s): NREL/SR-520-34568; AAD-9-18668-07; TRN: US201015%%730
• Resource Relation: Related Information: Work performed by the University of California at San Diego, La Jolla, California
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
ALLOYS
EPITAXY
NITROGEN
PHOTOLUMINESCENCE
QUANTUM WELLS
SOLAR CELLS
SUBSTRATES
SUPERLATTICES
PV
GAINNAS
DIGITAL-ALLOY
MIGRATION-ENHANCED EPITAXY (MEE)
PHOTOLUMINESCENCE (PL)
METAL-ORGANIC CHEMICAL VAPOR DEPOSITION
STRAIN-INDUCED
SPLITTING
SHORT-PERIOD SUPERLATTICE (SPSL)
Solar Energy - Photovoltaics