Doping concentration dependence of the photoluminescence spectra of n-type GaAs nanowires
- Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089-0271 (United States)
In this letter, the photoluminescence spectra of n-type doped GaAs nanowires, grown by the metal organic chemical vapor deposition method, are measured at 4 K and 77 K. Our measurements indicate that an increase in carrier concentration leads to an increase in the complexity of the doping mechanism, which we attribute to the formation of different recombination centers. At high carrier concentrations, we observe a blueshift of the effective band gap energies by up to 25 meV due to the Burstein-Moss shift. Based on the full width at half maximum (FWHM) of the photoluminescence peaks, we estimate the carrier concentrations for these nanowires, which varies from 6 × 10{sup 17} cm{sup −3} (lightly doped), to 1.5 × 10{sup 18} cm{sup −3} (moderately doped), to 3.5 × 10{sup 18} cm{sup −3} (heavily doped) as the partial pressure of the disilane is varied from 0.01 sccm to 1 sccm during the growth process. We find that the growth temperature variation does not affect the radiative recombination mechanism; however, it does lead to a slight enhancement in the optical emission intensities. For GaAs nanowire arrays measured at room temperature, we observe the same general dependence of band gap, FWHM, and carrier concentration on doping.
- OSTI ID:
- 22591673
- Journal Information:
- Applied Physics Letters, Vol. 108, Issue 18; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CHARGE CARRIERS
CHEMICAL VAPOR DEPOSITION
DOPED MATERIALS
GALLIUM ARSENIDES
NANOWIRES
ORGANOMETALLIC COMPOUNDS
PARTIAL PRESSURE
PHOTOLUMINESCENCE
SILANES
SPECTRA
TEMPERATURE RANGE 0273-0400 K