Momentum of ion bombardment in sputtering deposition process, which strongly depends on internal stress of thin film, has been evaluated regarding to a new parameter P_i we previously proposed for fine-tuning of mechanical, optical, electrical and magnetic properties. In this study, we demonstrate to estimate the Pi defined as (i/a) p, where i the ion flux, a the atom flux and p the ion’s momentum, by means of Langmuir probe and multi-grid analyzer in a function of negative bias voltage applied on substrates V_sub. As a result, it was found that the P_i was roughly proportional to V_sub except on lower voltage than 30 V. This indicates that the P_i should be measured plasma-diagnostically under incident ion energy as low as plasma potential.

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This paper proposes an investigation about the PV solar panel I-V characteristic to find a way to distinguish between normal cells and hot-spot cells depending on the changes of the panel output current. The current changes will help to design the real-time hot-spot detection system. In case if partial shadowing is applied to the PV panel, the system is equipped with a DSP to give an immediate judgment if hot-spot arises from one of the cells or not. From the experimental results, it is clarified that the hot-spot cells can be determined by calculating the current rate depending on the difference in the current divided by the short circuit current.

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