Wide gap II-VI semiconductors have strong second order susceptibilities χ(2) and are therefore promising materials for efficient second harmonic generation. We have grown high quality single crystalline ZnSe/ZnTe/ZnSe/GaAs (001) waveguides by metalorganic-vapor-phase-epitaxy. Using end-fire coupling we observe a phase matched signal of the 1170.5 nm fundamental wave. The fundamental beam is generated by a tuneable KTP optical-parametric-oscillator pumped by a ps-Ti:sapphire laser system. Phase matching is achieved by coupling the TE0 fundamental mode with the TM2 second harmonic mode within the symmetric ZnTe waveguide.

No abstract

Laser single side contact formation (LSSC) and the hydrogen passivation process are studied and developed for crystalline silicon thin film (CSiTF) solar cells on graphite substrates. The results demonstrate that these two methods can improve cell performance by increasing the open circuit voltage and fill factor. In comparison with our previous work, we have achieved an increase of 3.4% absolute cell efficiency for a 40 μm thick 4 cm 2 aperture area silicon thin film solar cell on graphite substrate. Current density-voltage (J-V ) measurement, quantum efficiency (QE) and light beam induced current (LBiC) are used as characterization methods.

No abstract

We present a thin-film crystalline silicon solar cell with an AM1.5 efficiency of 11.5% fabricated on welded 50 μm thin silicon foils. The aperture area of the cell is 1.00 cm 2 . The cell has an open-circuit voltage of 570 mV, a short-circuit current density of 29.9 mA cm −2 and a fill factor of 67.6%. These are the first results ever presented for solar cells on welded silicon foils. The foils were welded together in order to create the first thin flexible monocrystalline band substrate. A flexible band substrate offers the possibility to overcome the area restriction of ingot-based monocrystalline silicon wafers and the feasibility of a roll-to-roll manufacturing. In combination with an epitaxial and layer transfer process a decrease in production costs can be achieved.