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In this paper, we approached a novel fabrication for non phosphor white light emitting diodes (LEDs) by the growth of AlGaN/InAlGaN doublehetero structures using by mixed-source hydride vapor phase epitaxy (HVPE) system with multi-sliding boat. It is unique crystal growth technology different from conventional HVPE and metal organic chemical vapor deposition (MOCVD) system using mixed metal source of aluminum, indium and gallium. The characterization of non phosphor white LEDs was examined by photoluminescence (PL) and electroluminescence (EL). The results of EL were found green and yellow emissions as spectrum peaks near 500, 550, and 610 nm definitely. The CIE chromaticity coordinates of white LEDs was measured at injection current 30 mA. Our results are nearly positions; at x ¼ 0:28 and y ¼ 0:31. Even though the LED needs more improved in optical properties, we demonstrated achieving phosphor-free solid-state white lighting.

The AlGaN layer has direct wide bandgaps ranging from 3.4 to 6.2 eV. Nowadays, it is becoming more important to fabricate optical devices in an UV region for the many applications. The high quality AlGaN layer is necessary to establish the UV optical devices. However, the growth of AlGaN layer on GaN layer is difficult due to the lattice mismatch and difference thermal expansion coefficient between GaN layer and AlGaN layer. In this paper, we attempted to grow the LED structure on GaN template by mixed-source HVPE method with multi-sliding boat system. We tried to find the optical and lattice transition of active layer by control the Al content in mixed-source. For the growth of epi layer, the HCl and NH 3 gas were flowed over the mixed-source and the carrier gas was N 2 . The temperature of source zone and growth zone was stabled at 900 and 1090 o C, respectively. After the growth, we performed the x-ray diffraction (XRD) and electro luminescence (EL) measurement. Key words Hydride vapor phase epitaxy (HVPE), AlGaN, Light emitting diode (LED), x-Ray diffraction (XRD), Electro luminescence (EL), Double heterostructure (DH)HVPE에

We report on the growth and characterization of nano and micro scale GaN structures selectively grown on the vertex of hexagonal GaN pyramids. SiO 2 near the vertex of hexagonal GaN pyramids was removed by optimized photolithgraphy process and followed by a selective growth of nano and micro scale GaN structures by metal organic vapor phase epitaxy (MOVPE). The pyramidal GaN nano and micro structures which have crystal facets of semi-polar {1-101} facets were formed only on the vertex of GaN pyramids and the size of the selectively grown nano and micro GaN structures was easily controlled by growth time. As a result of TEM maesurement, Reduction of threading dislocation density was conformed by transmission electron microscopy (TEM) in the selectively grown nano and micro GaN structures. However, stacking faults were newly developed near the edge of SiO

In this paper, the selective area growth (SAG) of SAG-UV light-emitting diode (LED) was performed by mixed-source hydride vapor phase epitaxy (HVPE) with a multi-sliding boat system. The SAG-UV LED consists of a Si-doped GaN layer, an Si-doped AlGaN cladding layer, an AlGaN active layer, an Zn-doped AlGaN cladding layer, and a Zn-doped GaN capping layer. All of the epitaxial layers of LED structure were grown consecutively with a multi-sliding boat system. Room-temperature electroluminescence (EL) characteristics show an emission peak wavelength of 330 nm at room temperature. The aging test result of SAG-UV LED shows that the current was changed from 27.7 to 31.2 mA during 170 h at room temperature. At the current-voltage (I-V ) measurement, the turn-on voltage of the SAG-UV LED is 3.5 V at room temperature. The value of the series resistance is about 200 . We find that the mixed-source HVPE method with multi-sliding boat system is possible to be one of the growth methods of ultra-violet LEDs with high quality epi-layer. #