Three-dimensional mapping of active compound semiconductor structures
Study Lead: Prof Oleg Kolosov, Lancaster University
Compound semiconductors (CS) are true workhorses of modern technology – from GaN street lights to GaAs based materials in telecommunication and solar cells. Majority of CS devices use ultra-thin layers, nanowires, or both. By varying their composition and dimensions, researchers in the Hub can drastically improve device performance, create new functionalities, and advance manufacturing processes. Unfortunately, three-dimensional (3D) geometry of devices means that their layers and interfaces are hidden, making their properties, a key to the device performance, difficult or impossible to analyse. To overcome this, our project develops a new platform that combines Lancaster invention of oblique Ar ion 3D nano-cross-sectioning with material sensitive scanning probe microscopy probing local mechanical, thermal and electrical properties of buried layers from few nanometres to few micrometres deep, over wide half a millimetre area, with nanometre scale resolution. This provides fast, efficient and comprehensive study of heteroepitaxial layers, quantum wells, nanowires and nanopillars of CS materials, mapping their 3D morphology, composition, defects, and electrical and thermal transport.