Highly efficient electroluminescence in sapphire and magnesia Articles uri icon

publication date

  • September 2014

start page

  • 291

end page

  • 295

volume

  • 153

International Standard Serial Number (ISSN)

  • 0022-2313

Electronic International Standard Serial Number (EISSN)

  • 1872-7883

abstract

  • Electroluminescence (EL) has been obtained and studied in two different wide band gap oxide crystals: MgO:Li (7.8 eV) and Al2O3:Mg (8.8 eV). EL requires crystal doping with Li or Mg to induce p-type conductivity and the formation of F-type centers which are the deep levels within the band gap for electron hole recombination. Oxidizing treatments are required in Al2O3:Mg to reach adequate conductivities. The main EL emissions are at 2.35 eV (528 nm) for MgO:Li crystals and at 3.8 eV (327 nm) for Al2O3:Mg. Trace impurities also produce EL in the visible region, their control may be used for color designed LEDs. (C) 2014 Elsevier B.V. All rights reserved.

subjects

  • Physics

keywords

  • electroluminescence; f-type centers; oxide crystals: mgo:li and al2o3:mg; light emitting diodes (leds); optical-properties; single-crystals; mgo crystals; alpha-al2o3; growth; oxide