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Title: Variations of ionization potential and electron affinity as a function of surface orientation: The case of orthorhombic SnS

We investigated the dependence of absolute SnS band-edge energies on surface orientation using density functional theory and GW method for all surfaces with Miller indices −3≤h,k,l≤3 and found variations as large as 0.9 eV as a function of (hkl). Variations of this magnitude may affect significantly the performance of photovoltaic devices based on polycrystalline SnS thin-films and, in particular, may contribute to the relatively low measured open circuit voltage of SnS solar cells. X-ray diffraction measurements confirm that our thermally evaporated SnS films exhibit a wide distribution of different grain orientations, and the results of Kelvin force microscopy support the theoretically predicted variations of the absolute band-edge energies.
Authors:
 [1] ;  [2] ; ; ;  [3] ;  [4] ;  [5]
  1. Colorado School of Mines, Golden, Colorado 80401 (United States)
  2. (United States)
  3. Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  4. Harvard University, Cambridge, Massachusetts 02138 (United States)
  5. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
Publication Date:
OSTI Identifier:
22300136
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 21; 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; DENSITY FUNCTIONAL METHOD; DISTRIBUTION; ELECTRIC POTENTIAL; EQUIPMENT; EV RANGE; GRAIN ORIENTATION; MICROSCOPY; MILLER INDICES; ORTHORHOMBIC LATTICES; PHOTOVOLTAIC EFFECT; POLYCRYSTALS; SOLAR CELLS; SURFACES; THIN FILMS; TIN SULFIDES; X-RAY DIFFRACTION