A Solid-State Multicolor Light-Emitting Device Based on Ballistic Electron Excitation

Abstract

It is demonstrated that a solid-state luminescent device based on ballistic electron excitation can be fabricated using blue- or red-light-emitting materials as a fluorescent film. This device is composed of an n-type Si substrate, a nanocrystalline porous polysilicon (nc-PPS) layer, an organic fluorescent film, and a semitransparent thin Au film. When a positive bias voltage higher than approximately 10 V is applied to the Au top contact, the device uniformly emits blue or red light. The light intensity sharply increases with increasing bias voltage. The measured luminescence band almost coincides with the original photoluminescence spectrum of the deposited fluorescent material. The results indicate that light emission is due to the luminescence excited by ballistic electrons generated in the nc-PPS layer under a high electric field. This device is useful for applications to multicolor ballistic lighting.