Hybrid Moth-Eye Structures for Enhanced Broadband Antireflection Characteristics

Hybrid moth-eye structures were proposed to enhance broadband antireflection properties. An ultralow average reflectance down to 0.11% over the solar spectral range has been achieved, which demonstrates a ${\sim}50$% enhancement in broadband antireflection capability as compared with corresponding uniform moth-eye structures. This is attributed to a smaller refractive index gradient with respect to structure height. These hybrid structures can be applied to solar cells for higher light-to-electricity conversion efficiency.