skip to main content

SciTech ConnectSciTech Connect

Title: Oxygen deficiency and Sn doping of amorphous Ga{sub 2}O{sub 3}

The potential of effectively n-type doping Ga{sub 2}O{sub 3} considering its large band gap has made it an attractive target for integration into transistors and solar cells. As a result amorphous GaO{sub x} is now attracting interest as an electron transport layer in solar cells despite little information on its opto-electrical properties. Here we present the opto-electronic properties, including optical band gap, electron affinity, and charge carrier density, for amorphous GaO{sub x} thin films deposited by pulsed laser deposition. These properties are strongly dependent on the deposition temperature during the deposition process. The deposition temperature has no significant influence on the general structural properties but produces significant changes in the oxygen stoichiometry of the films. The density of the oxygen vacancies is found to be related to the optical band gap of the GaO{sub x} layer. It is proposed that the oxygen deficiency leads to defect band below the conduction band minimum that increases the electron affinity. These properties facilitate the use of amorphous GaO{sub x} as an electron transport layer in Cu(In,Ga)Se{sub 2} and in Cu{sub 2}O solar cells. Further it is shown that at low deposition temperatures, extrinsic doping with Sn is effective at low Sn concentrations.
Authors:
;  [1] ; ; ;  [2]
  1. Helmholtz-Zentrum Berlin für Materialien und Energie, Schwarzschildstraße 3, 12489 Berlin (Germany)
  2. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)
Publication Date:
OSTI Identifier:
22489287
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 2; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AFFINITY; CHARGE CARRIERS; ELECTRICAL PROPERTIES; ENERGY BEAM DEPOSITION; GALLIUM OXIDES; LASER RADIATION; LAYERS; OXYGEN; PULSED IRRADIATION; SOLAR CELLS; STOICHIOMETRY; THIN FILMS; TRANSISTORS