可撓式矽基光伏元件應用於室內光能量採集之研究

Abstract

氫化非晶矽薄膜太陽能電池有一定優勢，包含低成本，較高的光吸收係數，此外低溫製程也使其可以製作於塑膠基板例如:PET(polyethylene terephthalate)、PEN(Polyethylene naphthalate)、PI(Polyimide)等等。非晶矽電池的頻譜響應為300nm到800nm，和室內照明光源的輻射分布相同，能有效轉換室內光，電池擁有高開路電壓(Voc)，可提供電路更高的操作電壓。因此非晶矽電池用於室內光發電是有潛力的，可應用於物聯網IoT晶片以及感測器等低功耗的元件作為電源供應。 本研究於PI基板上製作n-i-p結構的可撓式非晶矽太陽能電池，以週期性排列的光捕捉結構和鋁背反射層應用於非晶矽太陽能電池，最佳化後的電池在照度為600 lux的T6日光燈管下得到輸出功率密度21.92 μW/cm2，利用並聯技術成功並聯兩顆1cm2的電池達到輸出功率41.76 μW。另外，電池可以承受以3mm彎曲半徑進行500次的彎曲、130℃的耐熱性測試、7個小時的室內光照射後沒有衰退，根據計算，並聯14顆1cm2的電池，可以達到0.56V的輸出電壓及518μA的輸出電流，將能用來在室內光下驅動3D定位裝置。

Hydrogenated amorphous silicon (a-Si:H) thin film solar cells have several advantages, including low cost, high light absorption coefficient, and low temperature process make it can be integrated with the plastic substrate For example: PET, PEN, and PI. Besides, frequency response of a-Si:H cells matches indoor light. Thus, a-Si:H cell has potential to be used f or indoor energy harvesting. The cells can be applied to “Internet of Things” and other low-power components as a power supply. In this study, a flexible a-Si:H solar cell with a n-i-p structure was fabricated on a PI substrate. A periodic light-trapping structure and an aluminum back-reflecting layer were employed in cells. High output power density of 21.92μW/cm2 is measured under T6 fluorescent tube with illumination of 600 Lux. Successfully connected two 1cm2 cells in parallel to achieve output power of 41.76 μW.. In addition, the cells can withstand 500 times bending with 3mm radius, 130℃ thermal test, and 7 hours exposure with indoor light. Connecting 14 cells with area of 1cm2 in parallel can achieve 0.56V output voltage and 518μA output current, which is sufficient to drive 3D positioning device under indoor light.