Acoustically driven emission of light in granular and layered semiconductors: recent advances and future prospects

Abstract

Acoustic driving techniques can produce luminescence in semiconductors quite efficiently. A mixture of grain particles, for example, emits light when driven by sufficiently intense acoustic fields. This effect is therefore particularly interesting for exploring the dynamics of granular solids. By applying this novel technique, further insight is gained when monitoring the driving-induced evolution of dense particle arrangements. Another subject in this article is the description of the basic physics that governs acoustically driven relaxation of photoexcited carriers in quantum well systems. Due to these properties, µs-prolonged recombination processes and periodic pumping of exciton emission in a quantum dot are observed, which offer new possibilities for tailoring multilayer structures of semiconductors. A variety of potential applications using these phenomena are envisaged.

Surface acoustic wave devices

“…At a certain region of at the sound path which is metallized, so that the surface is short circuited there and the electric field accompanying the SAW vanishes, the holes and electrons can recombine by emitting light. With this method is possible to "transport" light from one place to the other [22,23] It is also possible to read out the properties of a surface acoustic wave device contactless, which is, e.g,. applied to identify trains or to sensor the air pressure in a tire of a car [24].…”