We report the fabrication and characterization of visible-blind GaN-based UV photodetectors with indium-tin-oxide (ITO)/GaN Schottky junctions. We have systematically studied the optimal growth conditions for the ITO layers. Responsivity of 0.041 A/W was obtained for the optimised ITO/GaN UV detectors at 350nm. The I-V characteristics show that the reverse leakage currents of the devices are strongly dependent on the deposition conditions of the ITO. The experimental results indicate that interfacial traps play an important role on the optoelectronic properties of the devices. To improve the ITO/GaN interface, a thin Ni layer was deposited between the ITO and the GaN. Our results show that this leads to significant improvements in the leakage current, low-frequency excess noise and the UV-to-visible rejection ratio.
|Number of pages||4|
|Journal||Physica Status Solidi (C) Current Topics in Solid State Physics|
|Publication status||Published - Jul 31 2006|
|Event||6th International Conference on Nitride Semiconductors, ICNS-6 - Bremen, Germany|
Duration: Aug 28 2005 → Sep 2 2005
ASJC Scopus subject areas
- Condensed Matter Physics