Efficiency Enhancement of III-V Triple-Junction Solar Cell Using Nanostructured Bifunctional Coverglass With Enhanced Transmittance and Self-Cleaning Property

We present bifunctional nanostructured (NS) coverglasses with enhanced transmittance and self-cleaning function for improving the efficiency of a photovoltaic (PV) module with an InGaP/GaAs/Ge triple-junction solar cell. Prior to the fabrication of NS coverglasses, theoretical investigations were carried out using a rigorous coupled-wave analysis method to determine the desirable glass nanostructures that can effectively enhance the light absorption of the PV module. The transmission properties of the fabricated NS coverglasses with different glass nanostructures were systematically analyzed by considering the absorption spectrum of three subcells of the solar cell in order to find the most effective NS coverglass for enhancing the photocurrent of the PV module and thereby improving the conversion efficiency. The PV module with the most effective NS coverglass showed 4.2% enhanced short-circuit current density and 4.3% enhanced efficiency compared with the PV module with a bare coverglass measured under one sun of the air mass 1.5 global, showing the necessity of integrating a finely designed NS coverglass to effectively improve the efficiency of various PV systems with multijunction solar cells.