Browsing by Author "Chung, Chen Chen"

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High-Quality 1 eV In(0.3)Ga(0.7)As on GaAs Substrate by Metalorganic Chemical Vapor Deposition for Inverted Metamorphic Solar Cell Application
(2011-07-01)
Hong Quan Nguyen
;
Chang, Edward Yi
;
Yu, Hung Wei
;
Lin, Kung Liang
;
Chung, Chen Chen
In(0.3)Ga(0.7)As layers were grown by metalorganic chemical vapor deposition using step graded buffer layers on different misoriented GaAs(001) substrates. Smooth-surface In(0.3)Ga(0.7)As film with a root mean square roughness of 1.9 nm was obtained with the growth temperature of 490 degrees C using a 10-step graded parabolic-like indium profile buffer layer on the surface with the 6 degrees-off cut toward the [111] direction. The threading dislocation density in the film was determined to be 1.2 x 10(6) cm(-2) by transmission electron microscopy. The photoluminescence results obtained at 300 and 77K indicate that very low recombination centers existed in the epilayer. (C) 2011 The Japan Society of Applied Physics
High-Quality 1 eV In0.3Ga0.7As on GaAs Substrate by Metalorganic Chemical Vapor Deposition for Inverted Metamorphic Solar Cell Application
(2011-07-01)
Hong Quan Nguyen
;
Chang, Edward Yi
;
Yu, Hung Wei
;
Lin, Kung Liang
;
Chung, Chen Chen
In0.3Ga0.7As layers were grown by metalorganic chemical vapor deposition using step graded buffer layers on different misoriented GaAs(001) substrates. Smooth-surface In0.3Ga0.7As film with a root mean square roughness of 1.9 nm was obtained with the growth temperature of 490 degrees C using a 10-step graded parabolic-like indium profile buffer layer on the surface with the 6 degrees-off cut toward the [111] direction. The threading dislocation density in the film was determined to be 1.2 x 10(6) cm(-2) by transmission electron microscopy. The photoluminescence results obtained at 300 and 77K indicate that very low recombination centers existed in the epilayer. (C) 2011 The Japan Society of Applied Physics
InGaP/GaAs Dual-Junction Solar Cell with AlGaAs/GaAs Tunnel Diode Grown on 10 degrees off Misoriented GaAs Substrate
(2012-08-01)
Yu, Hung Wei
;
Chung, Chen Chen
;
Wang, Chin Te
;
Hong Quan Nguyen
;
Binh Tinh Tran
InGaP/GaAs dual-junction solar cells with different tunnel diodes (TDs) grown on misoriented GaAs substrates are investigated. It is demonstrated that the solar cells with P++-AlGaAs/N++-GaAs TDs grown on 10 degrees off GaAs substrates not only show a higher external quantum efficiency (EQE) but also generate a higher peak current density (J(peak)) at higher concentration ratios (185 x) than the solar cells with P++-GaAs/N++-InGaP TDs grown on 6 degrees off GaAs substrates. Furthermore, the cell design with P++-AlGaAs/N++-GaAs TDs grown on 10 degrees off GaAs substrates does not generate a disordered InGaP epitaxial layer during material growth, and thus shows superior current-voltage characteristics. (c) 2012 The Japan Society of Applied Physics
The Growth and Fabrication of High-Performance In0.5Ga0.5As Metal-Oxide-Semiconductor Capacitor on GaAs Substrate by Metalorganic Chemical Vapor Deposition Method.
(2012-01-01)
Hong Quan Nguyen
;
Hai Dang Trinh
;
Yu, Hung Wei
;
Hsu, Ching Hsiang
;
Chung, Chen Chen
Growth conditions have investigated for growing high quality In0.3Ga0.7As and In0.5Ga0.5As on GaAs substrate by metalorganic chemical vapor deposition method. Annihilation reactions between threading dislocations observed by transmission electron microscopy are experimental evidences to confirm threading dislocations had been blocked in InxGa1-xAs buffer layers. A high quality smooth surface In0.5Ga0.5As epi-film with threading dislocation density of 2x10(6) cm(-2) was achieved at growth temperature of 490 degrees C. Metal-oxide-semiconductor capacitor devices fabricated on In0.5Ga0.5As/GaAs perform nice capacitance-voltage response, with small frequency dispersion. The conductance contours indicate that the Fermi level moves freely to the lower part of the InGaAs bandgap without pinning.