Photovoltaic Mini-modules Using Silicon on Insulator Technology

This work shows the design, fabrication process, and characterization of photovoltaic c-Si mini-modules using Silicon on Insulator technology. Arrays consist of a monolithically series connection of small area photovoltaic cells (<1 mm2), and they are fabricated in a common substrate (active layer) of very thin thickness (~10 mum). Isolation between cells is performed by means of anisotropic etching of the active layer, and mechanical stability is done thanks to a handle wafer joined with the active layer trough a buried oxide. First results, using standard solar light (AM1.5 100 mW/cm2), confirm the viability of this technology to fabricate small area arrays, yielding single cell open circuit voltages Voc's about 0.55 V and photocurrent current densities around 21.3 mA/cm2. Series connection is also demonstrated increasing Voc from 0.55 V to 5.1 V when 9 cells are connected in series.