Naoki Taneda

Continuous silica glass fiber produced by sol-gel process

Abstract We have developed a new industrial technology related to the sol-gel process for manufacturing continuous silica glass fiber. This process has remarkable features such that the fiber can be made at temperatures below 1000° C. The sol-gel derived fiber contains very few impurities, and both shrinkage and drop in strength at high temperatures are much lower than those of fused silica glass fiber. With these features the fiber and its products can be used as electronic materials and thermal insulation at high temperatures.

TiO2-Coated Transparent Conductive Oxide (SnO2:F) Films Prepared by Atmospheric Pressure Chemical Vapor Deposition with High Durability against Atomic Hydrogen

The durability of textured transparent conductive oxide (TCO) thin films against atomic hydrogen was investigated. An ultrathin TiO2 layer of 2 nm thickness was deposited on textured fluorine-doped tin oxide (SnO2:F) films, successively by atmospheric pressure chemical vapor deposition (AP-CVD). TCO films with a TiO2 layer showed a higher optical transmittance and a lower resistivity after exposure to atomic hydrogen excited by very high frequency (VHF) plasma, while TCO films without a TiO2 layer showed a lower optical transmittance and a higher resistivity after the exposure. These TCO films were characterized by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) before and after the exposure to atomic hydrogen.

Fabrication of A-Si:H Solar cells on high haze SnO 2 :F thin films

In this work we report on the properties of amorphous silicon (a-Si:H) p-i-n solar cells fabricated on glass substrates covered with extremely high haze fluorinedoped tin oxide (SnO2:F) transparent conductive oxide (TCO) thin films, HU-TCO. The HU-TCO shows high haze value thorough the whole optical region where a-Si:H and microcrystalline silicon (μc-Si:H) solar cells are sensitive. We demonstrate here that open-circuit voltage (Voc) and fill factor (FF) of a-Si:H solar cells fabricated on HU-TCOs does not decrease significantly compared to the cells on conventional pyramidal texture TCOs. We also demonstrate here that Voc and FF of a-Si:H solar cells depend on not only surface morphology of TCOs, but also strongly depend on thickness and deposition conditions of the solar cells.

Improved light-trapping effect in a-Si:H / μC-Si:H tandem solar cells by using high haze SnO 2 :F thin films

In this paper we report on the fabrication of amorphous silicon (a-Si:H) / microcrystalline silicon (μc- Si:H) p-i-n tandem solar cells on high haze fluorine-doped tin oxide (SnO2:F) transparent conductive oxide (TCO) thin films, type-HU. The HU-TCO has double texture morphology on its surface and shows high haze value through the whole optical region where the tandem solar cells are sensitive. We demonstrate here that light-trapping effect is improved by using HU-TCO. HU-TCO provided higher short-circuit current than conventional pyramidal TCO when i-layer thicknesses of a-Si:H and μc- Si:H of tandem solar cell were 0.35 and 1.5 µm, respectively. Quantum efficiency of bottom μc-Si:H cell was improved by 1 mA/cm2 by using HU-TCO.