Porous GaN produced by CVD: progress in development and characterization

Identifier:  TDX:2661

Handle: https://hdl.handle.net/20.500.11797/TDX2661

Authors:  Mena Gómez, Josué

Abstract:
Gallium nitride (GaN) is a wide band gap semiconductor with important applications in white-light LEDs, which are an attractive alternative to conventional light sources due to its long operation lifetime, physical robustness, small-sized units, and minimal environmental impact. GaN, in its porous form, is expected to enhance the light extraction of these LEDs. In the recent years GaN has also attracted the attention of the sensors world, and many prototypes have been fabricated using HEMT devices. Porous GaN based sensors are expected to enlarge the contact surface against which the analyte can interact, increasing the sensitivity of the devices. Moreover, making these sensors specific for a given target can be achieved by chemically functionalizating the surface of the device. The main objective of this thesis is to optimize the growth conditions for the fabrication of porous GaN, as well as the growth of Mg- and Si-doped porous GaN and InGaN in order to be able to fabricate devices based on p.n junctions in the future. In this thesis, the study of the chemical functionalization with silanes and diazonium salts of the GaN surface in order to further fabricate efficient and selective sensors, has been also approached. Nanoporous GaN particles and epitaxial layers were synthesized in a single step by chemical vapor deposition (CVD) through the direct reaction between gallium and ammonia. For the doping of the porous particles and layers magnesium acetylacetonate and silicone acetate were chosen as Mg and Si precursors, respectively, in order to generate the p- and n-type semiconductors, respectively. The obtained results show promising advances for the fabrication of porous p-n junction-based devices and the functionalization of GaN surfaces for sensing applications.