Thin Multicrystalline Silicon Solar Cells With High Mechanical Strength and Less Light-Induced Degradation

Abstract

Cost reduction and efficiency promotion are well-known development directions faced by the photovoltaic industry, and the thin Si solar cell has been identified as a potential candidate to conquer the field. In this article, 120- μ m-thick p-type thin multicrystalline silicon (mc-Si) solar cells with a structure based on a full Al back surface field and an efficiency comparable to 180- μ m-thick solar cells were fabricated using a conventional production line. The mechanical strength and light-induced degradation effect for the 120- μ m-thick mc-Si solar cells were investigated. Our study shows that 120- μ m-thick mc-Si cells have greater mechanical strength with a bending displacement of 15.87 mm compared with 180- μ m-thick solar cells (7.87 mm), which can facilitate the development of advanced flexible solar cell modules. An important finding of this work is that thin mc-Si solar cells show a weaker light-induced degradation (LID) effect than 180- μ m-thick solar cells. A ∼ 2.7% (relative) degradation in efficiency ( η ) was observed for the 120- μ m-thick thin mc-Si solar cells following a one month exposure test. A thin Si solar cell with a promising new type of structure may also be expected to achieve a high η , a low LID effect, and a flexible capability in the near future.