Yu Zen Tsai

Porous SiO 2 /MgF 2 broadband antireflection coatings for superstrate-type silicon-based tandem cells

The purpose of this study is to reduce the glass substrate reflectivity over a wide spectral range (400-1200 nm) without having high reflectivity in the near-infrared region. After making porous SiO₂/MgF₂ double-layer antireflection (DLAR) thin film structure, the superstrate-type silicon-based tandem cells are added. In comparison to having only silicon-based tandem solar cells, the short-circuit current density has improved by 6.82% when porous SiO₂/MgF₂ DLAR thin film is applied to silicon-based tandem solar cells. This study has demonstrated that porous SiO₂/MgF₂ DLAR thin film structure provides antireflection properties over a broad spectral range (400-1200 nm) without having high reflectivity at near-infrared wavelengths.

Improvement of short-circuit current density in p-Ni 1-x : Li/n-Si heterojunction solar cells by wet chemical etching

This study confirms that the surface texturation of window layer (Al-Y codoped ZnO) etched by diluted HCl effectively increases conversion efficiency of p-Ni1-x O:Li/n-Si heterojunction solar cells. The results show that the short circuit current density (Jsc) of cell etched at 10 s increases about 8.5% compared to unetched cell, which also corresponds to the increase of efficient photoelectric conversion in NIR region as shown in external quantum efficiency spectra. It is attributed to the increase of light transmittance of AZOY thin films in the NIR region and the effective light path of the NIR wavelength, which results in increasing of light absorption in the base layer.

Simple broadband anti-reflective coatings for superstrate-type silicon-based tandem cells

In this paper, the superstrate-type silicon-based tandem cells between air and glass are added to a porous SiO2/MgF2 double-layer anti-reflective (DLAR) thin film structure in order to improve the glass substrate low reflectivity in a wide spectral range (400-1200 nm), without high reflectivity in the near-infrared region. Practical discussion is presented, as well as experimental results of fabricated films and devices. Application of the experimental porous SiO2/MgF2 DLAR thin film to conventional silicon-based tandem solar cells results in improvement of the short-circuit current density by 6.82%. Solar cell efficiency is improved by 7.14%. The presented experimental porous SiO2/MgF2 DLAR thin film structure provides anti-reflective results in a broad range of visible light, without high reflectivity at near-infrared wavelengths.