An investigation of the optical properties of disordered silicon nanowire mats

作者：Bao, Hua; Zhang, Weixia; Chen, Liangliang; Huang, Haoxiang; Yang, Chen; Ruan, Xiulin^*

来源：Journal of Applied Physics, 2012, 112(12): 124301.

DOI：10.1063/1.4768913

• PHOTOVOLTAIC APPLICATIONS
• TRANSPORT-PROPERTIES
• RANDOM-MEDIA
• ABSORPTION ENHANCEMENT
• MULTIPLE-SCATTERING
• ARRAYS
• WAVES

Optical reflectance spectra of three disordered silicon nanowire mats with average diameters of 40, 60, and 80 nm are investigated both experimentally and theoretically. The total hemispherical reflectance spectra from 200 to 1600 nm wavelength are first measured. All three samples exhibit reflectance about 15% to 20% within the ultraviolet band. As the wavelength becomes longer, the reflectance will first increase to around 50% and then decrease to below 20%. Such reflectance spectra are attributed to the combined effect of silicon dielectric function, the nanowire geometry, and the volume fraction of the mats. An analytical method based on Mie scattering theory and two-flux model is proposed to predict the reflectance spectra of the NW mats using only the physical quantities including dielectric function and structural parameters of the nanowire mats. The experimental reflectance spectra can be well reproduced by this method.

• 单位
  上海交通大学