Study of black silicon obtained by deep reactive ion etching - approach to achieving the hot spot of a thermoelectric energy harvester

摘要

In this paper we study the enhanced absorption properties of microano structured silicon surface under incident electromagnetic (EM) illumination and then its capacity to convert light to heat. We then simulate the optical reflectance of the 3D microano silicon cones of different dimensions. Equipped with the favorable simulation results we fabricate black silicon with excellent anti-reflectivity by using deep reactive ion etching (DRIE) under cryogenic temperatures. Reflectance measurement with an integrating sphere is approximately 1% in the optical wavelength range. Following this, black silicon with integrated resistance temperature detector (RTD) is developed to investigate its efficiency of the photo-thermal conversion.