ABSTRACT
In optoelectronic devices or optical components, the suppression of surface reflections caused by discontinuity of the refractive index (RI) between two different optical media is crucial. For instance, the efficiency of a photovoltaic device is primarily limited by the Fresnel reflection loss on the surface of the device. Such a reflection loss is especially highlighted in materials with a high RI such as Si, GaAs, and GaP. Other optoelectronic devices, including light-emitting diodes (LEDs), laser diodes, and photodetectors, have similar problems [1,2]. A “ghost image” in glasses and other transparent materials is also generated by the Fresnel reflection loss [3]. Thin-film technology is commonly used for mass production of antireflection coatings (ARCs) with quarter wavelength stacks. However, it shows antireflection (AR) properties only in specific wavelength ranges and for limited incidence angles. Additionally, thin-film multilayers have problems with material appropriateness, thermal mismatch, and instability of the stacks [4].
