Shuo-Ting You

Electrical contact for wurtzite GaN microdisks

We developed a back processing to fabricate an electrical contact of wurtzite GaN microdisk on transparent p-type GaN template. The interface welding between the GaN microdisk and p-type GaN template produced a very solid and secure epi-film contact for the electrical current passing through, with a resistance of 45.0 KΩ and threshold voltage of 5.9 V. The back processing can resolve the obstacle of electrical contacts for self-assembled wurtzite nano-devices.

Finite growth of InGaN/GaN triple-quantum-well microdisks on LiAlO2 substrate

We have grown high-quality InxGa1-xN/GaN triple-quantum-well microdisks on LiAlO2 substrate by plasma-assisted molecular beam epitaxy. The InxGa1-xN/GaN microdisk with a hexagonal shape of oblique face 28o-angle off c-axis was achieved. The mechanism of the termination of awl-shaped growth and the growth rates of GaN-barrier and InxGa1-xN-well were evaluated and confirmed with the triple quantum wells. Based on the growth rates and 28o-angle geometric shape, one can control the finite size of InGaN/GaN microdisks by plasma-assisted molecular beam epitaxy.

Epitaxial growth of M-plane GaN on ZnO micro-rods by plasma-assisted molecular beam epitaxy

We have studied the GaNgrown on ZnO micro-rods by plasma-assisted molecular beam epitaxy. From the analyses of GaN microstructure grown on non-polar M-plane ZnO surface ( 10 1 0 ) by scanning transmission electron microscope, we found that the ZnGa2O4 compound was formed at the M-plane hetero-interface, which was confirmed by polarization-dependent photoluminescence. We demonstrated that the M-plane ZnO micro-rod surface can be used as an alternative substrate to grow high quality M-plane GaN epi-layers.

The growth of heteroepitaxial CuInSe2 on free-standing N-polar GaN

We report that chalcopyrite CuInSe2 thin films were grown on free-standing N-polar GaN (0001) by molecular beam epitaxy. X-ray diffraction showed that the CuInSe2 thin film was grown in (112) orientation, and its peak of rocking curve with full width at half maximum of about 897.8 arc-sec indicated the epitaxial growth of CuInSe2 (112) film on N-polar GaN. Microstructure analysis of the CuInSe2  showed that the large lattice mismatch (28.5%) between CuInSe2  and GaN is accommodated by domain matching, and no interface reaction occurs between CuInSe2 and GaN. Our experimental results show that GaN is stable for the epitaxial growth of CuInSe2 thin film, which exhibits a promising potential for optoelectronic applications.