Black silicon – optical properties and applications

Author

Sita Rajyalaxmi Marthi, New Jersey Institute of Technology

Document Type

Dissertation

Date of Award

12-31-2017

Degree Name

Doctor of Philosophy in Materials Science and Engineering - (Ph.D.)

Department

Committee for the Interdisciplinary Program in Materials Science and Engineering

First Advisor

N. M. Ravindra

Second Advisor

S. Basuray

Third Advisor

Eon Soo Lee

Fourth Advisor

Michael Jaffe

Fifth Advisor

Anthony Fiory

Sixth Advisor

Jacob Timothy Trevino

Abstract

Crystalline Silicon (c-Si) is one of the most abundant and widely used semiconductors. Si is a semiconductor with indirect bandgap. The average reflectance of Si is about 30% in the visible range of wavelengths. Standard Si solar cells are not entirely useful in the infrared spectrum region. In order to make Si useful in a wide spectral range, the surface of Si is modified to reduce the reflectance of Si. The silicon thus modified is called Black Silicon (BSi).

This dissertation describes the model based on effective medium approximation to determine the effective optical constants, refractive index and extinction coefficient of BSi. The simulated optical properties of BSi are compared with the corresponding experimental values of BSi and c-Si. Application of Helmholtz’s law of optical reciprocity to the two-layer medium of BSi on crystalline silicon is examined. Influence of coatings and passivation on the optical properties of BSi is studied. The optical properties of passivation layers such as SiO₂, Si₃N₄ and Al₂O₃, on BSi are investigated in the wavelength range of 0.4 to 2.4 μm. A novel approach of using BSi as absorbing material in uncooled microbolometers is studied. The performance parameters of BSi based microbolometer are evaluated.

Recommended Citation

Marthi, Sita Rajyalaxmi, "Black silicon – optical properties and applications" (2017). Dissertations. 1790.
https://digitalcommons.njit.edu/dissertations/1790