Efficiency analysis depending on oxidation under normal atmospheric conditions and cell receiver development for concentrator photovoltaic modules

In this study, a concentrator photovoltaic (CPV) panel has been developed by using GaInP/GaAs/Ge triple junction solar cells. The CPV panel consists of 144 cells, each with a surface diameter of 2 mm, and Fresnel lenses formed with one Polydimethylsiloxane (PDMS) polymer for each cell. Receivers are used to mount cells to the panel. 9 cells have been placed on 1 receiver. In the system, there are 16 cell receiver in total. Lenses cause high temperatures on the cell surface in consequence of the Sun's rays are concentrated on the cell. Temperature is a factor that reduces the working performance of solar cells. Another feature of cell receivers is to transmit the heat coming to the cells to the lower layers. So, cells can work more efficiently. The experimental setup to investigate this effect consists of a receiver and also 9 cells and 9 lenses placed on this receiver. When temperature measurements are made with a solar simulator and under 1 Sun, it has been observed that the receiver transmits the heat falling on the cell surface to the lower layers and it reduces the temperature of the cell. Although solar cells are the most valuable material of a photovoltaic system, the importance of the receivers used for the efficient operation of the cells is obvious; therefore the receivers designs are suitable for improvement as much as CVP panel designs. Materials that increase the conductivity can make receivers even more useful. For this purpose, the receiver surface has been covered with different conductive materials in this study. Oxidation should also be considered to determine the materials. Under the usual atmospheric conditions, Under the usual atmospheric conditions, an oxide film formed over time on the surface of metal materials decays the thermal and electrical conductivity of the material. In this case, the efficiency of the photovoltaic system decreases. For this reason, it is important that the coating materials and metal parts used should be selected for both air oxidation resistant and inexpensive materials. Metal materials used are generally Au, Ag,Ni. Measurements have been made by solar simulator and under the Sun have shown a negligible loss in efficiency, around 0.1 % over a four-years period. As a result, using Ni as a coating material is advantageous in terms of obtaining high efficiency at low cost. The importance of energy need and developing technology accelerate the researches of solar cells. As shown in this thesis, the designed CPV panel is highly promising because of its superiority in efficiency. It also takes up less space than panels created with standard Si solar cells. These advantages demonstrate the importance of development of CPV panels.