Publication: Photo-Induced Conductivity of Heterojunction GaAs/Rare-Earth Doped SnO2
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Date
Advisor
Coadvisor
Graduate program
Undergraduate course
Journal Title
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Volume Title
Publisher
Univ Fed Sao Carlos, Dept Engenharia Materials
Type
Article
Access right
Acesso aberto
Abstract
Rare-earth doped (Eu3+ or Ce3+) thin layers of tin dioxide (SnO2) are deposited by the sol-gel-dip-coating technique, along with gallium arsenide (GaAs) films, deposited by the resistive evaporation technique. The as-built heterojunction has potential application in optoelectronic devices, because it may combine the emission from the rare-earth-doped transparent oxide, with a high mobility semiconductor. Trivalent rare-earth-doped SnO2 presents very efficient emission in a wide wavelength range, including red (in the case of Eu3+) or blue (Ce3+). The advantage of this structure is the possibility of separation of the rare-earth emission centers, from the electron scattering, leading to an indicated combination for electroluminescence. Electrical characterization of the heterojunction SnO2:Eu/GaAs shows a significant conductivity increase when compared to the conductivity of the individual films. Monochromatic light excitation shows up the role of the most external layer, which may act as a shield (top GaAs), or an ultraviolet light absorber sink (top RE-doped SnO2). The observed improvement on the electrical transport properties is probably related to the formation of short conduction channels in the semiconductors junction with two-dimensional electron gas (2DEG) behavior, which are evaluated by excitation with distinct monochromatic light sources, where the samples are deposited by varying the order of layer deposition.
Description
Keywords
tin dioxide, gallium arsenide, heterojunction, interface, electrical conductivity
Language
English
Citation
Materials Research-ibero-american Journal Of Materials. Sao Carlos: Univ Fed Sao Carlos, Dept Engenharia Materials, v. 16, n. 4, p. 831-838, 2013.
