We made a new type of high bias maetal-insulator-metal light-emitting junctions(Al-Al

2

O

3

-MgF

2

-An(Cu)]

which emit visible optical radiation when biased at voltages in the range 6-11V.The highest applied bias that the light-emitting devices can stand

and the output of per unit area and the corresponding power conversion efficiency werehigher than before metal-oxide-metal type light-emitting tunnel junctions.For the first time

the present paper report and argue this optical radiation excisted by the Schottky hot electrons and its physical picture:the hot electrons in the negative electrode areforced to positive electrode by the exerted electrical field through Schottky effect and then excite at An(Cu)-vacuum interface surface plasmon-polarition(SPP)

which are in turn coupled to external radiation through surface roughness.This picture is supported by measurement of current-voltage(

I

-

V

)and current-temperature(

I

-

T

)characteristics of the light-emitting devices

and by the observed light emission spectra from the lightemitting devices.