High Contrast Thin Film Electroluminescent Deyice with a GaAs Absorption Layer

An ITO/BaTi0₃ /ZnS:Mn/black insulator/Al ac thin film electroluminescent display device with high display viewability has been developed for the application in the automotive dashboard display.

The device consists of back and front insulating layers and a ZnS:Mn luminescent layer. The back insulating layer consists of the GaAs light absorption layer and the H_f O₂ insulating layer. This device exhibits high contrast ratio (greater than 2:1) in an ambient illumination of 10,000 ft-candle at 125 ft-L brightness.

This high contrast device also shows low power consumption due to placement of the black GaAs absorption layer between H_f O₂ insulating layers in the back side. This is a significant improvement over previously published results. Detailed experimental results will be presented.