We have fabricated high-efficiency a-Si/µc-Si tandem solar cells and modules with a very high µc-Si deposition rate using Localized Plasma Confinement CVD to give very high-rate deposition (>2.0 nm/s) of device-grade µc-Si layers. For further progress in productive plasma-CVD techniques, we have studied plasma phenomena by combining newly developed plasma simulation and plasma diagnosis techniques that reveal the importance of non-emissive atomic hydrogen. We also have proposed a model of defective µc-Si formation on highly textured substrates in which the atomic H in plasma is assumed to play an important role. We are also developing a non-vacuum deposition technique that we term “Liquid Si Printing.” A new record conversion efficiency for HIT solar cells of 24.7% has been achieved using a very thin c-Si wafer (Thickness: 98 µm, Area: 102 cm2).

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We developed a high-conversion-efficiency, a-Si/IlC Si tandem solar module using Ilc-Si thin film on a Gen. 5 class glass substrate. The stabilized module efficiency was 10.7% (initial module efficiency: 12.0%). We prepared high performance a-Si/Jlc-Si tandem solar cells based on our original technology for J.1c-Si thin films with localized plasma confinement chemical vapor deposition, optical confinement techniques, and laser patterning. To obtain higher conversion efficiency, optical confinement techniques are crucial, especially transparent conductive oxide (TCO) controlling technology. However, high-performance TCO includes steep valleys in the texture structure. Therefore, many defective regions are generated in the deposition of Jlc-Si thin film that degrade the solar cell performance. In this study we structurally identified these defective regions and propose a new formation model of the defective regions.

We consider intermediate frequency electrostatic drift modes in the UMIST magnetic quadrupole, with one and two full wavelengths along a closed magnetic field line. The dispersion curves and the shape of the longitudinal eigenfunctions are calculated. The effect of variations of various parameters is also studied. In particular, we conclude that whereas resonant non-linear interactions between the drift modes are possible for some parameter values, the interaction may be strongly non-resonant for other parameter values. Physica Scripta 49