Toshiyuki Komatsu

Glow discharge polycrystalline silicon thin‐film transistors

Thin‐film transistors were fabricated from polycrystalline silicon films which were produced by glow discharge decomposition of silane at 500 °C on thermal oxidized silicon substrates. The dependence of the crystalline and electrical properties was observed for thicknesses from about 500 to 4500 A. As the film grew thicker, the strongly (110) oriented polycrystalline structures became predominant. The conductivity changed from 4×10−9 to 10−6 (Ω cm)−1 and the activation energy from 0.57 to 0.5 eV. The field‐effect mobility of these thin‐film transistors also varied with the thickness of the film.

Stability and new structure in a-Si:H photoconductive sensors

Abstract In a-Si:H photosensors with gap cell configuration, decrease in photo-current with time was measured in light soaking at 20, 200 and 2000 μW/cm2 for 1000 hours. We derived an empirical equation agreeing well with the results, and found that the density of excited carriers plays a primary role in decrease in photocurrent. We also proposed a new structure for a-Si:H photosensor stabilized under light soaking.