Electroluminescent SrS and BaS Thin Films Deposited by ALD Using Cyclopentadienyl Precursors

Electroluminescent (EL) SrS and BaS thin films were deposited by the atomic layer deposition (ALD) technique using cyclopentadienyl-based metal precursors. The films were doped either with Cu, Ce, Pb, Mn, or Eu. BaS:Mn and BaS:Eu thin films were deposited for the first time by the ALD. The usable range of deposition temperatures was wide, but results of this and earlier ALD studies indicate that high deposition temperature is needed for the high emission intensity. It is shown that emission intensities and colors of the EL devices are comparable with the earlier ALD and chemical vapor deposition studies. It is also suggested that the dopant precursors have stronger impact to the emission than the host metal precursors, and that the use of the cyclopentadienyl-based dopants may result in further improvements in the performance of EL devices. The double-peak nature of Mn emission is also reported in both SrS and BaS, which is suggested to originate from at different crystal sites. © 2004 The Electrochemical Society. All rights reserved.