We report the characterization of the InGaN/GaN multi-quantum-well (MQW) light-emitting diode (LED) grown on a patterned sapphire substrate by metal organic chemical vapor deposition (MOCVD) using the selective area growth (SAG) method. The SAG patterns were designed to be circular and their diameters were 700 and 200 m. After the growth, the InGaN/GaN MQW LED of 200 m diameter had various crystal facets and a shape similar to volcanic craters, which were not observed in the 700-m-diameter sample. We obtained an active layer with compositional nonuniformity and superior optical properties. We found wide electroluminescence (EL) spectral peaks near 470, 570, and 600 nm. The distribution of the EL spectrum of the sample was similar to that of a conventional phosphor-converted white LED.

We investigated the effects of piezoelectric field on the electro-absorption characteristics in InGaN/GaN multiple-quantum well (MQW) green light emitting diodes (LED). Double crystal X-ray diffraction measurement was performed to study the crystalline property and indium (In) composition in the MQW active layer. To measure the electro-luminescence and electro-reflectance (ER) spectroscopy, we fabricated the 1×1 mm 2 large-area green LED chip. The piezoelectric field inside the LED structure was evaluated from the V comp in active layer by the ER spectra. Finally, we analyzed the electro-absorption characteristics of the green LED by using the photo-current spectroscopy.

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CuInGaSe (CIGS) mixed-source was prepared by hydride vapor transport method (HVT). The new source synthesis method was attempted by mixing several metals such as Cu, In, Ga, and Se with 3:5:1:4 mass ratios. This mixed-source was soaked at 1090 °C for 90 min in nitrogen atmosphere. Then, the CIGS was grinded up and formed the state of powder and the CIGS pellet was made by pressure machine. The diameter of pellet is 10 mm. The CIGS thin film was deposited on soda lime glass with evaporated molybdenum layer by e-beam evaporating this CIGS pellet. For crystallization of CIGS thin film, we measured scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). High intensity X-ray peaks diffracted from (112), (204)/(220), (116)/(312), and (400) of CIGS thin film and from (110) of Mo were confirmed by XRD measurement.