Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 39: Photovoltaics II

HL 39.4: Vortrag

Mittwoch, 24. März 2010, 10:15–10:30, H3

Thin film solar cells prepared on polycrystalline seed layers using low temperatures — •C. Jaeger¹, T. Matsui², M. Takeuchi², M. Karasawa², D. Wozniak¹, M. Kondo², and M. Stutzmann¹ — ¹Walter Schottky Institut, Technische Universität München, Garching, Germany — ²Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan

High costs and large material consumption are the main drawbacks of single crystalline Si wafer-based solar cells. Therefore, alternative methods using thin films are heavily investigated today. In this work, we present data from solar cells with PECVD-Si as the absorber material prepared on polycrystalline seed layers. For the seed layer preparation, the reverse aluminum-induced layer exchange (R-ALILE) process is used. In a R-ALILE process, a substrate/amorphous silicon/oxide/Al layer stack is annealed at temperatures below 570°C, leading to a layer exchange and the crystallization of the silicon. After the layer exchange is completed, a substrate/Al (+Si)/oxide/polycrystalline silicon film structure is formed.

We found that the proper treatment of the seed layers prior to the absorber layer deposition is crucial for a good solar cell performance. We studied different wet chemical methods (HF-solution, Al-etch) and the influence of an hydrogen plasma treatment. Furthermore, we investigated the influence of an additional Ag/ITO-back contact on the solar cell performance. We found that solar cell efficiencies over 5% can be obtained using the presented seed layer concept.