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Title: Broadband antireflection and absorption enhancement of ultrathin silicon solar microcells enabled with density-graded surface nanostructures

Density-graded surface nanostructures are implemented on ultrathin silicon solar microcells by silver-nanoparticle-catalyzed wet chemical etching to enable near-zero surface reflection over a broad wavelength range of incident solar spectrum as well as non-zeroth order diffraction and light trapping for longer wavelength photons, thereby achieving augmented photon absorption for ultrathin silicon microcells in a simple, cost-effective manner. The increase of absorbed photon flux through the “black silicon (b-Si)” surface translates directly into the corresponding enhancement of photovoltaic performance, where 5.7-μm b-Si microcells with the rational design of device configuration exhibit improved energy conversion efficiency by 148% and 50% with and without a diffuse backside reflector, respectively, compared to devices from the bare silicon without b-Si implementation. Systematic studies on nanostructured morphology, optical and electrical properties of b-Si microcells, together with semi-empirical numerical modeling of photon absorption, provide key aspects of underlying materials science and physics.
Authors:
; ; ; ;  [1] ;  [1] ;  [2]
  1. Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089 (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22300109
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; DENSITY; DIFFRACTION; EFFICIENCY; ELECTRICAL PROPERTIES; ENERGY CONVERSION; NANOSTRUCTURES; OPTICAL PROPERTIES; PHOTONS; PHOTOVOLTAIC EFFECT; REFLECTION; SILICON; SILICON SOLAR CELLS; SILVER; SPECTRA; SURFACES; THIN FILMS; TRAPPING; WAVELENGTHS