Towards 400 mV ALICIA thin-film silicon solar cells on glass

Polycrystalline silicon (pc-Si) is a promising candidate for thin-film photovoltaics. In this paper, the advantages, evolution of the technology, and the latest results of ALICIA pc-Si solar cells on glass are presented. ALICIA stands for aluminium-induced crystallisation ion-assisted deposition. In the ALICIA technology, a polycrystalline seed layer is formed on borosilicate glass by AIC (aluminium-induced crystallisation) and epitaxially thickened by non-ultra-high vacuum ion-assisted deposition (IAD). The key factors which led to the improvement of the open-circuit voltage from 130 mV in June 2003 to 386 mV in June 2004 are discussed. Furthermore, an ALICIA solar cell with a 1-Sun energy conversion efficiency of 2.2 % is presented. The short-circuit current density is 11.4 mA/cm² and the V_oc is 380 mV. These results were achieved by an optimisation of the temperature profile of the epitaxial growth process, by rapid thermal annealing (RTA), and by an increased hydrogenation temperature (∼480 °C). The presented results confirm that ALICIA is a very promising thin-film PV technology.