Description of the project:

 

The project joins the Romanian research efforts aiming to develop the scientific knowledge concerning micro and nanotechnologies and nanostructured materials. The project approaches an important direction of the Romanian research – elaboration, fabrication and implementation of advanced new technologies leading to an increased competitive autochthonous production, beeng in a good agreement with thematic area S/T 4.4.

The project purposes to design and fabricate high efficiency and low cost PV solar cells (S/T 5.2) on different substrates, using non-conventional technologies and nanostructured materials.  IMT’s experience as coordinator in different national research programs, consisting in texturised solar cells on monocrystallin p-silicon (100) and (111) oriented realization, determined the interest in this domain of other Romanian research teams, having as a consequence the creation of a Consortium, to continue in common the research, trying to increase the PV solar cells light conversion efficiency.

The texturisation of solar cells surfaces obtained by IMT using different etching solutions allowed the significant decrease of the incident light reflection under 5 %. This method applied to the PV solar cells leads to an important growth of the incident light capture onto the structure surface, resulting the increment of the solar cells efficiency to over 20%.

By assembling the cells into arrays / matrix onto solar panels it is possible to obtain high energies (solar converted into electrical), of 60 – 110 W/m2.

The poly Si thin films came into attention of the researchers for their use to PV solar cells, due the fact of a better charge carrier mobility and a better lightening stability. Due to the surface roughness, so presenting grains that behaves as trapping centers for the minority carriers, the poly Si thin films presenting adequate graininess are demanded in photovoltaic applications. The oxidic materials (nano powders) are used for the fabrication of reflective layer on the texturised surface – method used for increasing the solar cells efficiency. The incorporation of the reflective layers (sol-gels) into the cells is controlled by spectrophotometric measurements which determines the optimum parameters of the texturised surface.

Main activities of the project:

·         The poly Si films will be deposed in IMT by LPCVD, and amorphous Si films by sputtering in ROMES;
·         The texturised surfaces will be deposited with poly-Si layers, or amorphous Si, and doped with sol-gel solutions and nanopowders by spinning in ICIA Cluj-Napoca, ICF, INCDMRR;
·         The  electrical characterization, functionality  and utility demonstration in ICPE SA;
·         The process modeling – UPB;
·         Technological fabrication, demonstration in IMT.

The validity  of the project is sustained by the existing network of research teams, formed by specialist groups that are proposing this theme, well sustained by their works and experience in the field of micro and nanotechnologies, microelectronic and micromechanic devices, silicon microprocessing, and  modeling, simulation and design programs used. The Romanian research teams proposed thematic research areas in good agreement with those of the CEEX program, so resulting the possibility of a next / future joint of the Research Reuropean Program in the PV domain, the Platform PT. 18 – photovoltaic cells.