Synthesis and characterization of thin film electroluminescent devices all-prepared by ultrasonic spray pyrolysis

Alternating current thin film electroluminescent devices have been fabricated using aluminum-doped zinc oxide (ZnO:Al) as transparent conducting layer, aluminum oxide (Al2O3) as insulating layers, and manganese-doped zinc sulfide (ZnS:Mn) as electroluminescent layer. All these films were deposited by the ultrasonic spray pyrolysis technique at the same temperature (450 degrees) on glass substrates, forming a standard MISIM (metal-insulator-semiconductor-insulator-metal) configuration. The electroluminescence of MISIM devices with a total thickness of similar to 1330 nm was investigated by applying a sinusoidal voltage with a frequency of 10 kHz. The devices showed orange-emission spectra centered at approximately 570nm, characteristic of T-4(1) -> (6)A(1) radiative transitions of Mn2+ ions in the ZnS host, with a sharp intensity increase upon increasing the root mean square voltage above a threshold of 25 V and a rapid saturation for voltages higher than 38 V. The electroluminescent emission of these MISIM structures can be observed with the naked eye under ambient illumination. (C) 2013 Elsevier B. V. All rights reserved.