Fotosil – Photoluminescent ions in the production of third-generation silicon-based photovoltaic cells
The FotoSil “Photoluminescent ions in the production of third-generation silicon-based photovoltaic cells” project was funded by the ministry of science & innovation under the 2008-2011 national plan for research, development and technological innovation, and more specifically the INNPLANTA 2011 sub-programme of scientific and technological activities conducted in science and technology parks. The grant totalled €808.088,00 (2011-2013), of which 70% was provided by the European Commission’s European Regional Development Fund (ERDF).
Photovoltaic solar energy is a renewable that is in constant evolution, and a key issue is the development of more efficient and cheaper solar cells. Achieving these improvements is paramount to encouraging large-scale integration of this renewable.
The overall aim of the FotoSil project was to produce more efficient, low-cost silicon-based photovoltaic cells, using third-generation solar cell technology to improve the absorption of photons, and obtain more efficient emitters (or top layers).
To this effect, it was necessary to develop different processes and technologies. Firstly, to develop processes for producing high-efficiency photovoltaic cells at lower cost. To do this, the processes for producing photovoltaic cells on monocrystalline substrate were analysed in an attempt to adapt those techniques to multicrystalline substrates. Currently, most solar cells are produced on multicrystalline substrates, because, although they are of lower quality, they are cheaper than monocrystalline substrates.
Secondly, there is a need to develop the means of producing more efficient emitters. More efficient emitters would result in more efficient electricity within the photovoltaic cell. This improvement was sought via two routes: on the one hand, the use of amorphous silicon films on textured surfaces; on the other hand, the use of selective emitters under the metal contacts, to promote power generation. Finally, to develop intrinsic amorphous silicon film depositing processes. The aim was to create an intermediate amorphous silicon film, so as to improve the emitter’s response to the most energetic photons in the UV-VIS wavelength range.
As well as improving production processes, efforts also focused on developing third-generation cell technologies. The behaviour of photoluminescent materials, such as rare earth and silicon nanostructures, used in combination as fotoconverters, was studied with the aim of increasing photoconversion efficiency, and therefore increasing solar cell performance.