Satoshi Arimoto

150 mW fundamental-transverse-mode operation of 670 nm window laser diode

Fundamental-transverse-mode high-power CW operation over 150 mW has been realized in AlGaInP/GaInP 670-nm window laser diodes. A window structure of Zn-induced-disordered GaInP has been fabricated by solid phase diffusion using ZnO film. A compressively strained double-quantum-well active layer and a multiple quantum barrier (MQB) also have been employed for reduction of threshold current. Stable CW operation beyond 1500 h has been observed under 50 mW at 50 degrees C. >

Simplified mass-production process for 16% efficiency multi-crystalline Si solar cells

We have developed a simplified mass-production process for 16% efficiency multi-crystalline silicon solar cells. In this paper, newly developed fabrication process without increasing process steps and applying expensive equipment is described. The main improved points are as follows: (1) novel texturing method using Na2CO/sub 3/: reduced fabrication cost compared to conventional NaOH+IPA etching; (2) optimization of PECVD temperature for SiN ARC; and (3) improved silver paste for fire-through of PECVD-SiN AR film: reduction of penetration into diffused n-layer during firing and finer line electrodes with high aspect ratio. By combining such novel technologies, 16% efficiency for 15 cm/spl times/15 cm cells has been obtained for four different suppliers mc-Si wafers.

Realization of high-power operation in AlGaInP lasers by employing multiquantum barrier and strained active layer

CW output power in excess of 60 mW at 110 degree(s)C with a fundamental-transverse mode and stable CW operation over 3000 hrs under 30 mW at 60 degree(s)C have been realized by employing a multiquantum well (MQW) active layer with optimized compressive strain. A window-structure laser fabricated by solid phase diffusion of Zn has exhibited high-power CW operation over 150 mW keeping the fundamental-transverse-mode. Systematical approach to the high power operation has also been discussed.

Thickness dependence of defect density in thin film silicon formed on insulator polycrystalline by zone-melting recrystallization [solar cells]

Formation technique of high quality thin film polycrystalline Si on insulator by zone-melting recrystallization (ZMR) was investigated for use in Si solar cell applications. Varying the thickness of polycrystalline Si of ZMR samples, thickness dependence of defect density in ZMR-Si films was studied. It was found that defect density of ZMR-Si film was strongly affected by thickness of polycrystalline Si. By thinning the polycrystalline Si film, defect density of ZMR-Si film was reduced to 3/spl times/10/sup 6//cm/sup 2/ without lowering scanning speed at ZMR process.

Characterization of thickness dependence on defect density and hydrogen passivation for thin film polycrystalline silicon solar cells

Thickness dependence on defect density and hydrogen passivation for thin film polycrystalline silicon solar cells fabricated by the zone-melting recrystallization (ZMR) technique are experimentally investigated. We confirmed that thinning of the active layer is available for increasing Voc for the cells with relatively high defect density (1/spl times/10/sup 6/-1/spl times/10/sup 7/ cm/sup -2/). At the same time, it was clarified that the effectiveness of hydrogen passivation is strongly dependent on the total amount of 3-dimensionally distributed defect in the active layer. Light-induced degradation phenomenon of hydrogen passivated cells was also investigated under the conditions of AM1.5, 125 mW/cm/sup 2/, and 48/spl deg/C. Significant degradation was not observed over 300 hours such as in hydrogenated amorphous silicon solar cells.