Intrinsic recombination and interface characterization in surface-free GaAs structures
- T.J. Watson Research Center, Yorktown Heights, NY (United States)
- Rensselaer Polytechnic Inst., Troy, NY (United States)
- Sandia National Labs., Albuquerque, NM (United States)
The authors report on a thorough photoluminescence (PL) and PL time-decay study of the interfacial passivating effects of metalorganic chemical vapor deposition prepared Al{sub 0.3}Ga{sub 0.7}As, n{sup +}-doped GaAs, and Na{sub 2}S surface barriers on epitaxial, high-purity (n{sup {minus}}) GaAs structures. They observed 300-K radiative lifetimes, in such 10-{mu}m structures, of 2.5 {mu}s, 800 ns, and 150 ns, respectively. Accompanying radiative efficiencies are 10{sup 3}-10{sup 4} higher in all of these epibased structures, and 10{sup 2} higher for Na{sub 2}S, than for corresponding bare GaAs surfaces. Further, from detailed PL lifetime studies versus GaAs thickness, they found the lowest interfacial recombination velocities reported for any GaAs/Al{sub x}Ga{sub 1-x}As structure, to date, of {approx lt}40 cm/s, and, correspondingly, 0-1,800 cm/s for n{sup +}/n{sup {minus}}/n{sup +} all-GaAs homostructures. Thus, virtually surface-free structures are now achievable. In comparison, they found at best, {approximately}5,500 cm/s for Na{sub 2}S, and typically 34,000 cm/s for bare GaAs surfaces. They conclude, on the basis of their detailed experimental study of a wide variety of samples, that these values provide truly reliable measures of surface recombination velocities for both surface types. They found that after demonstrating that minority-carrier recombination kinetics in their ideal structures are truly intrinsic, and thus wholly unaffected by extrinsic processes, they examine the temperature dependence of band-to-band and free-exciton recombination. They fully explain all intrinsic, free-carrier recombination found in each structure, for temperatures of 40-300 K through rate equations appropriate to each structure. Similar low-temperature (1.8-40 K) studies confirm dominant decay proceeds, here, by intrinsic free excitons.
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 7115698
- Report Number(s):
- CONF-910115--
- Journal Information:
- Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States), Journal Name: Journal of Vacuum Science and Technology. B, Microelectronics Processing and Phenomena; (United States) Vol. 9:4; ISSN 0734-211X; ISSN JVTBD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360606* -- Other Materials-- Physical Properties-- (1992-)
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
ELECTRICAL PROPERTIES
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
INTERFACES
JUNCTIONS
KINETICS
MATERIALS
MATHEMATICAL MODELS
N-TYPE CONDUCTORS
OPTICAL PROPERTIES
P-N JUNCTIONS
P-TYPE CONDUCTORS
PHYSICAL PROPERTIES
PNICTIDES
RECOMBINATION
SEMICONDUCTOR JUNCTIONS
SEMICONDUCTOR MATERIALS