Takahiro Ide

Efficient Free-Exciton Recombination Emission from Diamond Diode at Room Temperature

Free-exciton recombination emission of 235 nm in wavelength is obtained by current injection at room temperature from a diamond-based pn junction diode composed of B-doped crystal grown by high-temperature, high-pressure synthesis and a S-doped homoepitaxial layer grown by the chemical vapor deposition method. The diode shows a clear rectification characteristic and a high external quantum efficiency of excitonic emission, 8×10-5, which indicates that the excitonic emission of diamond is a good candidate for application to semiconductor UV-light-emitting devices. A defect-induced light emission and large leakage current indicate that a higher UV emission efficiency is expected with improvement of the junction quality.

A Multi-layer Eddy Current Micro Sensor For Non-destructive Inspection Of Small Diameter Pipes

We have developed a multi-layer eddy current micro sensor. The dimension of the sensor is 3mm x 3mm x 80 pm. It was composed of one to four layers of micro spiral coil made of 10 x 10 pm2 copper lines. The number of turn in each layer is 40 turns. In the present work, we report on the fabrication and the evaluation of multi-layer eddy current micro sensors in both experiments and 3D FEM analysis.