Photoluminescence and electroluminescence of ZnO:Zn layers prepared by a chemical vapor deposition method with ethanol addition

ZnO:Zn phosphor layers were prepared from ZnCl2 at relatively lower temperatures between 500 and 600 degrees C by a chemical vapor deposition method. Ethanol vapor was added in the deposition process. It produced the partially reducing conditions to form Zn-rich ZnO. The green photoluminescence (PL) around 500 nm was much enhanced by the ethanol addition. The highest PL intensity was obtained when the deposition temperature was 550 degrees C and 0.03 mol% ethanol was added to the gas. The effect of the ethanol addition was suppressed at temperatures higher than 600 degrees C, which was probably due to the complete decomposition of ethanol into H2O and CO2. The ZnO:Zn layers showed electric conductivity, and orange electroluminescence (EL) was emitted from the uncovered layers directly connected to the lead wires when ac-voltage was applied. The chromaticity coordinates of the EL was (0.52, 0.40). (C) 2007 Elsevier B.V. All rights reserved.