高效超薄空间用三结砷化镓太阳电池研制

High-efficiency and ultra-thin triple-junction space solar cell

高效性、轻型化是未来单体太阳电池的发展方向。采用金属有机物化学气相沉积(MOCVD)法制备高效Ga In P/Ga As/Ge正向晶格匹配三结砷化镓外延片,先采用机械磨削方式减薄到一定厚度,再通过氢氟酸、双氧水和水的混合液将衬底减薄至120、100、80μm,最薄至50μm。设计新型背电极,解决超薄片翘曲问题。通过以上手段制备成不同厚度和不同面积的砷化镓太阳电池,利用厚度50μm的外延片,制备出最大面积为12.25 cm2的太阳电池,其光电转换效率为29.52%(AM0,25℃)。利用厚度80μm的外延片,制备出最大面积为30.18 cm2的太阳电池,其光电转换效率为29.7%(AM0,25℃)。经过温度冲击、焊点拉力和稳态湿热等可靠性试验考核,均满足要求。

High-efficiency and lightweight are the development of solar cell. High-efficiency Lattice Match GaInP/GaAs/Ge wafer was prepared by MOCVD, and then mechanical grinding was first adopted to reduce the thickness of the Ge substrate to certain extent. The wafer was then immersed to mixed aqueous solution composed of hydrofluoric acid and hydrogen peroxide to reduce its thickness to 120 μm, 100 μm, 80 μm and 50 μm. Finally, the wafer was taken to fabricate to solar cell with different thickness and different area. Bending stress caused by thinner thickness was reduced by new back electrode design. Solar cell specimen efficiency with thickness of 50 μm and area of 12.25 cm2 has reached 29.52%（AM0, 25 ℃）, and solar cell specimen efficiency with thickness of 80 μm and area of 30.18 cm2 has reached 29.7%（AM0, 25 ℃）. Reliability tests such as thermal cycling, strength test, and humidity and temperature were adopted to make sure the products meet the application＇s requirement.