Efficiency Enhancement of GaAs Single-Junction Solar Cell by Nanotextured Window Layer

In order to improve efficiency of flexible III-V semiconductor multi-junction solar cells, it is important to enhance the current density for efficiency improvement and to attain an even efficiency of solar cells on a curved surface. In this study, the nanotextured InAlP window layer of a GaAs single-junction solar cell was employed to suppress reflectance in broad range. The nanotextured surface affects the reflectance suppression with the broad spectrum of wavelength, which causes it to increase the current density and efficiency of the GaAs single-junction solar cell and alleviate the efficiency drop at the high incident angle of the light source. Those results show the potential of the effectively suppressed reflectance of multi-junction solar cells and even performance of solar cells attached on a curved surface.

Improving the efficiency of GaAs solar cells using a double semi-transparent carbon nanotubes thin layer

To investigate the efficiency of a single-junction solar cell that was performed using a numerical analysis method, the effect of creating several different surface-enhancer layer structures on the efficiency of the solar cell was performed. In this study, several carbon nanotube structures adapted to the solar cell structure of the gallium arsenide (GaAs) substrate were used. These elements have two important features of transparency and conductivity. Here, the effect of various parameters such as structure type, dimensions, number of layers, usable impurities and their arrangement on the solar cell efficiency was investigated. In this research, the layer added on the surface of a solar cell can be modeled on a heterogeneous carbon nanotube network. Finally, an optimized single-junction solar cell was obtained by examining the performance of the solar cell using the final carbon nanotube layers. This work resulted, the solar cell with a combination of a double-layer carbon nanotube enhancer by about 30% of efficiency, due to the ability to absorb more photons in one layer of the nanotubes, and better electrical transferability in the other layer of the nanotubes. In this solar cell, two different layers of carbon nanotube with a surface ratio of 10% and 90% of the total surface enhancer layer were used, with a cellular efficiency of about 1% improvement in performance compared with the previous one.