New step impact electroluminescent devices

Abstract

The step impact electroluminescent devices (SIED) and the multistep photon amplifier converted (SPAC) are proposed. The devices are a multilayered heterojunction structures in which the accelaration and collision excitation processes are spatially separated and permits independent optimization of each function in different materials. In collision excitation region, ballistic electrons excite the rare earth ions by direct impact. By changing conduction band step Δ E c we can tune up the energy of excited electrons to the resonance condition of a particular excited state of RE 3+ ions. The emission from the rare earth ions with transition wavelength shorter than semiconductor's band edge emission can be generated. The emission will contain narrow lines with gradual change in wavelength with temperature. The advantages of the new devices and excitation mechanism as discussed in detail. Laser action should also be obtainable by properly choosing device geometry. The laser oscillation at the rare earth transition assure the same wavelength from devices to devices with weak temperature dependence. The SIED structure is very promising structure for studying the direct impact excitation mechanism for a localized impurity in semiconductors. It can be used as a general tool for studying the excitation function of RE 3+ ions and other impurities with internal transitions like some transition metal impurities in III–V compounds.