Sound Emitting Thin Film Electroluminescent Devices Using Piezoelectric Ceramics as Insulating Layer

Abstract

A novel electroluminescent (EL) device which emits a sound as well as a light is proposed. This sound emitting EL device has the same structure as the insulating ceramic EL (ICEL) device reported in recent years [1,2]. The EL device consists of a thin film light emitting layer and a piezoelectric ceramic plate. The ceramic plate which is substrate of the device acts not only as a sound emitter but also as an insulating layer. In this paper, we demonstrate the sound emitting EL device fabricated using a manganese-doped zinc sulfide (ZnS:Mn) thin film as the light emitting layer and a barium titanate (BaTiO₃) ceramic plate as the insulating layer. Details of the response of electroluminescence and sound emission in this device to an applied alternating current (ac) voltage in the audio frequency are also described.