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Title: Solar energy conversion via hot electron internal photoemission in metallic nanostructures: Efficiency estimates

Collection of hot electrons generated by the efficient absorption of light in metallic nanostructures, in contact with semiconductor substrates can provide a basis for the construction of solar energy-conversion devices. Herein, we evaluate theoretically the energy-conversion efficiency of systems that rely on internal photoemission processes at metal-semiconductor Schottky-barrier diodes. In this theory, the current-voltage characteristics are given by the internal photoemission yield as well as by the thermionic dark current over a varied-energy barrier height. The Fowler model, in all cases, predicts solar energy-conversion efficiencies of <1% for such systems. However, relaxation of the assumptions regarding constraints on the escape cone and momentum conservation at the interface yields solar energy-conversion efficiencies as high as 1%–10%, under some assumed (albeit optimistic) operating conditions. Under these conditions, the energy-conversion efficiency is mainly limited by the thermionic dark current, the distribution of hot electron energies, and hot-electron momentum considerations.
Authors:
; ;  [1] ;  [2] ;  [3] ;  [2]
  1. Thomas J. Watson Laboratories of Applied Physics, California Institute of Technology, Pasadena, California 91125 (United States)
  2. (United States)
  3. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States)
Publication Date:
OSTI Identifier:
22273700
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 13; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 14 SOLAR ENERGY; ABSORPTION; ELECTRIC CONDUCTIVITY; ELECTRONS; ENERGY EFFICIENCY; INTERFACES; NANOSTRUCTURES; PHOTOEMISSION; SCHOTTKY BARRIER DIODES; SEMICONDUCTOR MATERIALS; SOLAR ENERGY CONVERSION; YIELDS