Yanfeng Wang

UV-photodetector based on NiO/diamond film

In this study, a NiO/diamond UV-photodetector has been fabricated and investigated. A single crystal diamond (SCD) layer was grown on a high-pressure-high-temperature Ib-type diamond substrate by using a microwave plasma chemical vapor deposition system. NiO films were deposited directly by the reactive magnetron sputtering technique in a mixture gas of oxygen and argon onto the SCD layer. Gold films were patterned on NiO films as electrodes to form the metal-semiconductor-metal UV-photodetector which shows good repeatability and a 2 orders of magnitude UV/visible rejection ratio. Also, the NiO/diamond photodetector has a higher responsivity and a wider response range in contrast to a diamond photodetector.In this study, a NiO/diamond UV-photodetector has been fabricated and investigated. A single crystal diamond (SCD) layer was grown on a high-pressure-high-temperature Ib-type diamond substrate by using a microwave plasma chemical vapor deposition system. NiO films were deposited directly by the reactive magnetron sputtering technique in a mixture gas of oxygen and argon onto the SCD layer. Gold films were patterned on NiO films as electrodes to form the metal-semiconductor-metal UV-photodetector which shows good repeatability and a 2 orders of magnitude UV/visible rejection ratio. Also, the NiO/diamond photodetector has a higher responsivity and a wider response range in contrast to a diamond photodetector.

Analysis of diamond pseudo-vertical Schottky barrier diode through patterning tungsten growth method

In this study, diamond pseudo-vertical architecture Schottky barrier diodes (PVSBDs) through the patterning tungsten growth method have been investigated. The forward current density is 16u2009A/cm2 at 5u2009V, and a rectification ratio is more than 5 orders of magnitude atu2009±5u2009V for diamond PVSBD. The reverse breakdown voltage is 640u2009V, and the corresponding electrical field is 4.57u2009MV/cm. These results are obtained by patterning tungsten (W) on the diamond surface as a blocking layer and growing a diamond epitaxial layer on the uncovered zone. A W/diamond ohmic contact was formed during the diamond epitaxial layer growth process. An aluminum film was used as a Schottky contact. Overall, the results illustrate that W patterned growth to fabricate PVSBD is efficient.

Ohmic contact between iridium film and hydrogen-terminated single crystal diamond

Investigation of ohmic contact between iridium (Ir) film and hydrogen-terminated single crystal diamond has been carried out with annealing temperature from 300 to 600u2009°C in argon (Ar) and hydrogen ambient. Electrodes were deposited on hydrogen-terminated single crystal diamond by electron beam evaporation technique, and specific contact resistivity has been measured by transmission line model. The interface between Ir film and hydrogen-terminated single crystal diamond was characterized by transmission electron microscopy and energy dispersive X-ray spectroscopy. Theoretical calculation value of barrier height between Ir film and hydrogen-terminated single crystal diamond was around −1.1u2009eV. All results indicate that an excellent ohmic contact could be formed between Ir film and hydrogen-terminated single diamond.