Choice of dielectrics for TFEL displays

The commonly used dielectrics, Y
2
O
3
, Al
2
O
3
, Si
3
N
4
, and Ta
2
O
5
, were evaluated for use in ac thin-film electroluminescent displays, along with a composite dielectric SiAlON. Adhesion, stress cracking, charge storage capacity, and display brightness and efficiency were studied for devices with ZnS: Mn layers fabricated under identical conditions. A combination of SiAlON and Ta
2
O
5
appears to be optimum as a double-layer dielectric system for ACTFEL displays.