Multicrystalline silicon thin film solar cells on glass with epitaxially grown emitter prepared by a two-step laser crystallization process

Abstract

In this paper, we demonstrate a two-step laser crystallization process for thin film silicon solar cells on glass. In a first step a 5 µm thick amorphous silicon layer is crystallized by a diode laser to get the absorber. The multicrystalline layer consists of grains with sizes in the range of 1 mm to 10 mm. In a second step a thin amorphous silicon layer is epitaxially crystallized by an excimer laser to form the emitter.Epitaxy was investigated in a fluence range of 700 to 1200 mJ/cm2. The resulting thickness of the emitter is measured and numerically simulated, both resulting in 185 nm for a fluence of 1100 mJ/cm2. The solar cells achieve maximum open circuit voltages of 548 mV, short-circuit current densities of up to 22.0 mA/cm2 and an efficiency of 8.0%.