Session GW: Plenary Session

Wednesday, October 6, 2010

Up-scaling of thin film silicon solar cells to industrial commercial products of over 1 m$^{2}$ module area is a highly challenging task. Hereby, the transfer of high efficiency device results obtained in small area research-type equipments to large area high performance R{\&}D and high productivity mass fabrication equipment are important issues needed to be solved. Especially the PECVD equipment in the thin film production line is one of the most important key elements to bring the module efficiency up and to reduce manufacturing costs. Oerlikon Solar uses a plasma excitation frequency of 40.68 MHz instead of the industrial standard frequency of 13.56 MHz for the amorphous and microcrystalline thin film silicon deposition due to the increased deposition rate and obtain ``softer'' plasma processes. In the first step, silicon deposition processes are developed and optimized in smaller R{\&}D KAI M systems. A stabilized record cell efficiency of 10.09{\%} has been obtained for a single-junction amorphous silicon solar cell device and independently confirmed by NREL (Golden, USA). Furthermore, a ``Micromorph'' (amorphous/microcrystalline silicon) tandem cell having a stabilized efficiency of 11.3{\%} has been manufactured. Both latter devices have been deposited in small R{\&}D KAI M systems using our LPCVD ZnO as front and back contact TCO. In the second step these process parameters are then transferred to industrial size PECVD reactors of 1.4 m$^{2}$ (KAI-1200). Following this strategy we achieved recently for amorphous silicon p-i-n single-junction and ``Micromorph'' tandems 1.4 m$^{2}$ R{\&}D modules having initial aperture efficiencies of 10.0{\%} respectively 11.0 {\%}. These remarkable efficiencies clearly demonstrate the high potential of the PECVD KAI systems. Based on these results, Oerlikon Solar as an equipment manufacturer is installing production facilities for amorphous silicon and ``Micromorph'' PV modules above 450 MW capacities for all its clients worldwide.   

Wednesday, October 6, 2010

It is demonstrated that nanoscopic processing in gas-phase, liquid-phase, and gas-liquid interfacial plasmas is effective in pioneering next-generation nanoelectronics and nanobio-fusion science. Actual materials to be targeted here for plasma-mediate functionalization are a nanocarbon family consisting of fullerenes, carbon nanotubes (CNTs), metal nanoparticles (MNPs), and biomolecules such as DNA. In the case of gas-phase plasmas, the mass synthesis of charge- and/or spin-exploited atom encapsulated (@) fullerenes is realized (Li@C$_{60}$, N@C$_{60})$ and under investigation (Ni@C$_{60})$ toward nano-biomedical applications. The structure controlled growth of high quality single-walled carbon nanotubes (SWNTs) with a narrow chirality distribution is also realized using the diffusion plasma-CVD method. Inner nanospaces of CNTs are controlled with the plasma-ion irradiation method, enabling various kinds of atoms and molecules @CNTs to display novel electrical, optical, and magnetic nanodevice-characteristics. In the liquid-phase case, single- and double-stranded DNA@CNTs are created by applying DC and RF electric fields in micro electrolyte plasmas. Versatile control of CNT semiconducting properties is achieved depending on each kind of encapsulated DNA bases such as cytosine and guanine. Photoinduced electron transport phenomena are also observed upon SWNT-DNA conjugates under the FET configuration, being applicable to photoswitching nanobio devices. Finally, gas-liquid interfacial plasmas are stably generated using a kind of fully-ionized liquid plasma, ionic liquids (ILs), in contact with gas discharge areas. Gas-phase plasma irradiation to the IL through electrostatic potential differences at the interface leads to the synthesis of MNPs and MNP-CNT conjugate. Then, based on the successive synthesis of MNP-DNA conjugate, (MNP-DNA)@CNTs are challenged to be created by superimposing pulse DC electric fields upon DC fields in the solid-liquid-gas interfacial regions. The results are expected to be available for developing innovative nanomedicine.