The properties of AlGaN epi layer grown by HVPE

Abstract

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

Anodic stripping voltammetry of silver(I) using unmodified GaN film and nanostructure electrodes

“…It possesses unique electrical properties, low toxicity and excellent chemical stability [13,14]. In particular, wurtzite gallium nitride (GaN), with its remarkable wide direct band gap energy, extremely chemical stability in harsh environment, superior optical property and convenient controlling over its carrier concentration and conductivity type, has been recognized as an attractive candidate for light-emitting diode (LED) [15][16][17], optoelectronic devices [18], DNA biosensor [19], anion and pH selective potentiometric sensor [20,21], monitoring pH in aqueous solution and certain gases at relatively high temperatures. The usage of unmodified GaN electrodes is of considerable attraction in anodic stripping voltammetry, as excellent chemical/electrochemical stability and resistance of the electrode surface provide potentially better reliability and reproducibility for analytical studies in silver metal detection than, for example, Hg electrode.…”