Room temperature ultraviolet emission at 357nm from polysilane based organic light emitting diode

Abstract

We have fabricated an organic light emitting diode using poly(n-butylphenylsilane) which has an emission in deep ultraviolet at 357nm at room temperature. The device structure used is glass/indium tin oxide/poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate)/polysilane (emitting material)/calcium/aluminum. These devices emit ultraviolet light with a turn-on voltage of 8V. The electroluminescence spectrum of the device in the ultraviolet range is identical to the photoluminescence spectrum of the polysilane thin film. From these devices, we also observe an additional emission in the visible region, which is not present in the photoluminescence spectrum of the material. The visible emission has a color coordinate of (0.36,0.35), which can be modulated to a required white light coordinate by down converting the ultraviolet emission.