Artigo
Photo-Induced Conductivity of Heterojunction GaAs/Rare-Earth Doped SnO2
Registro en:
Materials Research-ibero-american Journal Of Materials. Sao Carlos: Univ Fed Sao Carlos, Dept Engenharia Materials, v. 16, n. 4, p. 831-838, 2013.
1516-1439
10.1590/S1516-14392013005000060
S1516-14392013005000060
WOS:000322727600019
S1516-14392013000400019.pdf
7730719476451232
0000-0001-5762-6424
Autor
Bueno, Cristina de Freitas [UNESP]
Oliveira Machado, Diego Henrique de [UNESP]
Pineiz, Tatiane de Fatima [UNESP]
Scalvi, Luis Vicente de Andrade [UNESP]
Resumen
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. Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Sao Paulo State Univ UNESP, Dept Phys, Sch Sci, Bauru, SP, Brazil Sao Paulo State Univ UNESP, Meteorol Res Inst, Bauru, SP, Brazil Sao Paulo State Univ UNESP, Dept Phys, Sch Sci, Bauru, SP, Brazil Sao Paulo State Univ UNESP, Meteorol Res Inst, Bauru, SP, Brazil