Experimental investigations of transport and optical properties of 3-5 quantum well structures grown via molecular beam epitaxy under optimal growth conditions
Abstract
Zero field mobilities in GaAs/Al(x)Ga(1-x)As(100) inverted HEMT structures in excess of 100,000 sq cm/V-Sec at LN2 temperatures were achieved . The possibility of high mobilities in square single quantum wells with modulation doping on the inverted interface side only is demonstrated. Photoluminescences linewidth dependence on the square single quantum well width shows inverse proportion rather than the inverse cubic proportion behavior expected from the popularly used notion of well width fluctuations. The observed behavior is shown to be consistent with fluctuations in the band edge discontinuity (i.e., well depth) arising from in-plane fluctuations in the alloy composition of the AlxGa(1-x)As barrier layers in high quality structures. Influence of an electric field across single and coupled-double quantum wells on their optical characteristics is examined theoretically and through photoluminescence, photocurrent, electroreflectance, photoreflectance and Photovoltage measurements. Exploiting growth conditions controlled thermodynamic and kinetic effects on facet formation and inter-facet migration, a unique in-situ method for realization of quantum wire and quantum box structures without the need for lithography or direct-write patterning on such small dimensions is demonstrated. Finally, some initial results on resonant tunneling diodes are reported.
- Publication:
-
California Univ., Los Angeles Report
- Pub Date:
- April 1989
- Bibcode:
- 1989ucla.reptQ....M
- Keywords:
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- Aluminum Gallium Arsenides;
- High Electron Mobility Transistors;
- Molecular Beam Epitaxy;
- Quantum Wells;
- Reflectance;
- Transport Properties;
- Crystal Structure;
- Electric Fields;
- Electron Mobility;
- Electron Tunneling;
- Heterojunctions;
- Modulation Doping;
- Photoluminescence;
- Photovoltaic Effect;
- Quantum Electronics;
- Resonance;
- Tunnel Diodes;
- Solid-State Physics