Characterization of Bismuth Telluride Thin Films Grown by MBE
Ladda ner
Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Wireless, photonics and space engineering (MPWPS), MSc
Publicerad
2013
Författare
Fülöp, Attila
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Bismuth telluride, Bi2Te3, has been predicted to be a topological insulator; it has however been difficult to manufacture good quality thin films of it. This project focuses on the characterization and analysis of bismuth telluride thin films that have been manufactured using molecular beam epitaxy in the Chalmers cleanroom. Substrate material and several growth condition parameters have been varied and are here analyzed using X-ray diffraction and atomic force microscopy to draw conclusions about the optimal growth conditions. It turns out that the growth mode of the bismuth telluride thin films changes when grown on vicinal vs. flat substrates. Other effects include a phase change from Bi2Te3 to Bi4Te3 when the tellurium flux is decreased below 20 times the bismuth flux. This phase change leads to the destruction of the topological insulator properties.
Beskrivning
Ämne/nyckelord
Materialvetenskap , Nanovetenskap och nanoteknik , Nanoteknik , Materials Science , Nanoscience & Nanotechnology , Nano Technology