Electronic properties of AlGaAs and AlGaAs/GaAs heterostructures

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:5253286

Leybovich, I S

The electronic properties of free-standing Al/sub x/Ga/sub 1-x/As epitaxial layers and Al/sub x/Ga/sub 1-x/AsGaAs heterostructures are investigated. The fact that the persistent-photoconductivity (PPC) effect is a property Al/sub x/Ga/sub 1-x/As is established experimentally by observing the PPC effect in four free-standing Al/sub x/Ga/sub 1-x/As layers with alloy composition 0.26 less than or equal to x less than or equal to 0.32. The investigated samples were grown by LPE, MBE, and MOCVD. Experimental values of n/sub H/ and ..mu../sub H/ at room temperature for free-standing Al/sub x/Ga/sub 1-x/As layers are obtained. The author observed and investigated a new effect in Al/sub 0.3/Ga/sub 0.7/AsGaAs heterostructures that they called thermally stimulated persistent conductivity. After a heterostructure is cooled (53-55 min.) from room temperature to low temperatures (120 to 140K), the electron concentration and mobility do not stay constant with time. Electron concentration decreases slowly (days) while Hall mobility increases. This effect is attributed to the properties of the two-dimensional electron gas (2DEG) formed at the heterointerface. Investigation of the PPC effect in a heterostructure indicates that two mechanisms are responsible: at first, PPC due to the AlGaAs epitaxial layer is dominant, while at a later stage PPC due to the properties of the heterointerface dominates

• Research Organization: Washington Univ., St. Louis, MO (USA)
• OSTI ID: 5253286
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
42 ENGINEERING
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
ALUMINIUM ARSENIDES
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HALL EFFECT
HETEROJUNCTIONS
INTERFACES
JUNCTIONS
PHOTOCONDUCTIVITY
PHYSICAL PROPERTIES
PNICTIDES
SEMICONDUCTOR JUNCTIONS