Imaging of carrier dynamics in semiconductor heterostructures by surface acoustic waves

✍ Scribed by M. Streibl; A. Wixforth; J.P. Kotthaus; C. Kadow; A.C. Gossard

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 175 KB
• Volume: 6
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00137-x

✦ Synopsis

Surface acoustic waves (SAW) are an ideal tool for the noninvasive detection of conductivity and carrier distributions in otherwise unstructured semiconductor systems. Here we demonstrate a technique that allows for spatially resolved experiments with a resolution of a few acoustic wavelengths. Extremely narrow acoustic paths, excited by tapered interdigital transducers, are employed to probe conductivity proÿles. The method is used to resolve the spatial form of a photogenerated electron-hole plasma and allows for the direct observation of room-temperature drag and transport of electrons and holes in the coherent phonon wind of an intense SAW beam. By the application of a tomographic technique we are able to reconstruct 2D charge distributions.