Professor

KURIBAYASHI Shizuma
Title Professor
Department Department of Mechanical Engineering
Course Mechanical Engineering Course

Research fields

We are now studing on photovoltaic power generation.The most important subject is to decrease the product cost. So we are developing a new PECVD method that enables to be a high deposition rate. A supersonic under-expanded jet in PACVD has enabled the maximum rate of 4.5 μm/s at 100 MHz VHF power of 0.8 W/cm2. The measured defect dennsity shows that good quarity of the film is promising, and the process required much less power than thermal plasma jet processes On the otherhand we also investigate to improve efficiency of a-Si/c-Si hetero-junction solar cell, it is important to realize high open circuit voltages in keeping with high short circuit currents. Ttextured c-Si substrates are introduced to achieve higher short circuit currents, but the open circuit voltages are still lower than about 700mV. We have detected the hetero-junction surface that is textured, and found obvious leak current parts localized at mountain ridges using by the photovoltaic microscopy system. Also we investigated the ralationship between the leak current and the life-time. (Life-time of minority carrier is well known to be rrelative to an efficiency of solar cell ) Because we suppose that detected leak current parts localized at mountain ridges are relative to the life-time, and we found that preliminary experiments showed obvious relativity between the leak current and the lie-time.

Fig.1 Si:H deposition rates at various distances from the nozzle Fig.2 Leak current parts localized at mountain ridges

Research Keywords

photovoltaic power generation, thin film Si solar cell, a-Si/c-Si hetero-junction solar cell

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