We demonstrate a 1.55-μm InAlGaAs/InP vertical-cavity surface-emitting laser grown by metal-organic chemical vapor deposition. AI₂O₃-Si thin-film pairs and InAlGaAs/InAlAs epitaxial layers are used as a top mirror and a bottom-side output coupler, respectively. Direct modulation characteristics through single mode fiber are reported in the speed of 2.5 Gbit/s. View full abstract»

C₆₀/amorphous carbon (a-C) superlattice structures were fabricated by shutter controlled molecular beam deposition. A-C layers were transformed from C₆₀ by nitrogen ion bombardment. The dark and photo conductivity of C₆₀/a-C superlattice structures were measured by gap-cell structure. The resulted films show high resistivity, and the photosensitivity ratio ranged from 9∼16. It is thought that such low photosensitivity is caused by high defect density of 2.7×10²¹ cm^-3 in the a-C layers. Use of hydrogen plasma in C₆₀ amorphization process, instead of nitrogen, reduces the spin defect density in two orders of magnitude. Hydrogen atoms effectively reduce the defect density of a-C films by etching the weak carbon bond structures and/or passivating the dangling bonds. View full abstract»

The use of the electrostatic voltmeter for the measurement of a.c. voltages in terms of d.c. standards is found to give rise to errors due to departure from unity of the ratio of the d.c. sensitivity of the instrument to the a.c. sensitivity. The effect appears to be due to semi-conducting films on the surfaces of the voltmeter elements, and is believed to be absent in voltmeters with working surfaces of freshly-cleaned platinum. View full abstract»

Effect of deposition temperature of monochamber PECVD processing on a-Si TFT electrical characteristics and stability has been investigated. The experimental results show that (1) TFTs deposited at 280°C have higher mobility than the TFTs deposited with other temperature; (2) TFTs deposited with higher temperature have better stability against voltage stressing. When we deposited SiN_x/ a-Si/n+a-Si films by monochamber PECVD processing at 280°C, a-Si:H TFTs have higher mobility and better capability against voltage stressing View full abstract»