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High-luminance electroluminescent devices have been newly developed using a Ga 2 O 3 :Mn thin film prepared by a sol-gel process. The sol-gel process, which eliminates the need for vacuum processes, enabled the inexpensive preparation of Ga 2 O 3 :Mn thin films on large-area thick ceramic sheet insulators. Gallium acethylacetonate, a relatively inexpensive and easy to handle material, was used as the Ga source material. Thin-film electroluminescent (TFEL) devices with a Ga 2 O 3 :Mn thin-film emitting layer prepared by the sol-gel process at a deposition temperature of 900 • C and a postannealing temperature of 1000 • C exhibited luminances of 1271 and 401 cd/m 2 when driven at 1 kHz and 60 Hz, respectively.

Ga2O3:Mn and (Ga2O3-SnO2):Eu thin films have been prepared by a sol-gel process. High luminance emissions were obtained in TFEL devices: green using a Ga2O3:Mn and red using a Ga2O3:Eu or a SnO2:Eu thin-film emitting layer. These sol-gel prepared devices were produced without using any vacuum processes and always exhibited higher luminances than equivalent devices prepared by r.f. magnetron sputtering: 40, 309 and above 1000 cd/m2 using SnO2:Eu, Ga2O3:Eu and Ga2O3:Mn phosphor thin films, respectively, in TFEL devices prepared by the sol-gel process and driven at 1kHz.

Articles you may be interested inPhotoluminescence and electroluminescence from Eu-activated Ca Al 2 O 4 -based multicomponent oxide thinfilm phosphorsHigh-luminance multicolor-emitting thin-film electroluminescent ͑TFEL͒ devices have been developed using a new Mn-and Cr-co-doped Ga 2 O 3 phosphor with variations of both Mn and Cr from 0 to a content of 20 at. %. Ga 2 O 3 :Mn,Cr TFEL devices driven at 1 kHz exhibited a change from green to red in emission color, maintaining luminances above 100 cd/m 2 , when the co-doped Cr content was varied from 0 to 20 at. % under a constant Mn content of 0.3 at. % doping. In addition, the emission color of a Ga 2 O 3 :Mn,Cr TFEL device co-doped with a Mn content of 0.3 at. % and a Cr content of 3 at. % changed from green to red with an increase of the applied voltage.