Combined micro- and nano-scale surface textures for enhanced near-infrared light harvesting in silicon photovoltaics

Nanotechnology. 2011 Mar 4;22(9):095201. doi: 10.1088/0957-4484/22/9/095201. Epub 2011 Jan 24.

Abstract

As silicon photovoltaics evolve towards thin-wafer technologies, efficient optical absorption for the near-infrared wavelengths has become particularly challenging. In this work, we present a solution that employs combined micro- and nano-scale surface textures to increase light harvesting in the near-infrared for crystalline silicon photovoltaics, and discuss the associated antireflection and scattering mechanisms. The surface textures are achieved by uniformly depositing a layer of indium-tin-oxide nanowhiskers on micro-grooved silicon substrates using electron-beam evaporation. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves over 90% external quantum efficiencies for a broad wavelength range of 460-980 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallization / methods
  • Electric Power Supplies*
  • Equipment Design
  • Equipment Failure Analysis
  • Infrared Rays
  • Light
  • Materials Testing
  • Nanostructures / chemistry*
  • Nanostructures / radiation effects*
  • Nanotechnology / instrumentation*
  • Silicon / chemistry*
  • Solar Energy*
  • Surface Properties

Substances

  • Silicon