ISSN:
1432-0630
Keywords:
72.20 F
;
72.80 E
;
73.40 L
;
73.60 F
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract A new artificial semiconductor superlattice with tunable electronic properties and simultaneously with significant mobility enhancement of both 2-dimensional electrons and 2-dimensional holes has been prepared by molecular beam epitaxy. The structure consists of a periodic sequence ofn-Al x Ga1−x As/i-GaAs/n-Al x Ga1−x As/p-Al x Ga1−x As/ i-Ga.As/p-Al x Ga1−x As stacks with undoped Al x Ga1−x As spacers between the intentionally doped Al x Ga1−x As and the nominally undopedi-GaAs layers. In this newheterojunction doping-superlattice we have for the first time achieved a spatial separation of electrons and holes by half a superlattice period as well as simultaneously a spatial separation of both types of free carriers from their parent ionized impurities. These unique properties are demonstrated by the strongly increased tunability of bipolar conductivity with bias. In addition, the observed temperature dependence of Hall mobilities provides direct evidence for a strong mobility enhancement of both electrons and holes in the spatially separated 2-dimensional accumulation channels formed in the lower band gap material.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00614907
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