We have fabricated the vertically aligned coaxial or longitudinal heterostructure GaN/InGaN nanowires. The GaN nanowires are first vertically grown by vapor-liquid-solid mechanism using Au/Ni bi-metal catalysts. The GaN nanowires are single crystal grown in the [0001] direction, with a length and diameter of 1 to 10 μm and 100 nm, respectively. The vertical GaN/InGaN coaxial heterostructure nan...

Three-fold symmetrically distributed GaN nanowire (NW) arrays have been epitaxially grown on GaN/sapphire substrates. The GaN NW possesses a triangular cross section enclosed by (0001), (2112), and (2112) planes, and the angle between the GaN NW and the substrate surface is approximately 62 degrees . The GaN NW arrays produce negative output voltage pulses when scanned by a conductive atomic fo...

We demonstrate the high efficiency of InGaN/GaN multiple quantum wells (MQWs) light-emitting diode (LED) grown on the electrochemically etched nanoporous (NP) GaN. The photoluminescence (PL) and Raman spectra show that the LEDs with NP GaN have a strong carrier localization effect resulting from the relaxed strain and reduced defect density in MQWs. Also, the finite-difference time-domain (FDTD...

Distributed Bragg reflectors (DBRs) are essential components for the development of optoelectronic devices. For many device applications, it is highly desirable to achieve not only high reflectivity and low absorption, but also good conductivity to allow effective electrical injection of charges. Here, we demonstrate the wafer-scale fabrication of highly reflective and conductive non-polar gall...

make GaN a superior material to Si and GaAs for the hightemperature high-power electronic devices, ultrahigh power switches, and microwave-power sources. [ 3 ] However, self-heating limits the performance of GaN devices and further development of GaN technology. [ 4 , 5 ] The temperature rise in high-power AlGaN/GaN heterostructure fi eld-effect transistors (HFETs), which is currently on order ...

In this paper, GaN-based light-emitting diodes (LEDs) with photonic quasi-crystal (PQC) structure on p-GaN surface and n-side roughing by nano-imprint lithography are fabricated and investigated. At an injection current of 20 mA, the LED with PQC structure on p-GaN surface and n-side roughing increased the light output power of the InGaN/GaN multiple quantum well LEDs by a factor of 1.42, and t...

...........................................................................................................................................1 CHAPTER I: INTRODUCTION ............................................................................................................2 OVERVIEW OF GAN HEMTS .......................................................................................................

We have investigated the effects of nonradiative recombination centers (NRCs) on the device performances of InGaN/GaN multi-quantum-well (MQW) light-emitting diodes (LEDs) incorporating low-temperature n-GaN (LT-GaN) underlying layers. Inserting an LT-GaN underlying layer prior to growing the MQWs is a successful means of separating the induced NRCs as a result of the presence of a growth inter...

Record-low sheet-resistance of $ 128 O=sq have been obtained in two-dimensional electron gases at ultrathin single AlN/GaN heterojunctions by optimizing the metal fluxes used in molecular beam epitaxy growth. Multiple 2DEGs have been found in AlN/GaN superlattices, with the net electron density measured 4 1 Â 10 14 cm À2 at room temperature. This very high electron density also leads to a furth...

We prepared 2”-GaN wafers as templates for a self separation process which is happening during cooldown after growing thick layers of GaN in our hydride vapor phase epitaxy (HVPE) reactor. Our templates process starts with GaN grown by metalorganic vapor phase epitaxy (MOVPE) directly on sapphire. These GaN layers are getting masked with 200nm of SiN that is structured by means of optical litho...