POLYCRYSTALLINE SILICON THIN-FILM SOLAR CELLS ON GLASS BY SOLID PHASE CRYSTALLIZATION OF IN-SITU DOPED EVAPORATED a-Si

摘要

Poly-Si thin-film solar cells were made on planar glass by solid-phase crystallization (SPC) of e-beam evaporated amorphous silicon (a-Si). A glass/n+n-p+ diode structure with a total a-Si thickness of ～2.5 μm was first prepared on glass by means of in-situ doped evaporated a-Si. Then, the a-Si was crystallised into poly-Si by SPC at 600 °C for a period of 48 hrs. After SPC, the solar cells received two follow-up treatments (first a rapid thermal anneal (RTA), then a plasma hydrogenation process) to improve their conversion efficiency. The structural properties of the cells were investigated by means of Raman spectroscopy and UV reflectance spectra. The electrical properties of the cells were characterized by quasi-steady-state open-circuit voltage measurements. It was found that the two follow-up treatments improve the 1-Sun Voc of the cells significantly, due to both an improved structural and an improved electronic material quality. Finally, using the RTA processed and hydrogenated material, mesa-type poly-Si cells were fabricated and characterised to demonstrate the potential of this new material to thin-film solar cells.