The innovation engine for new materials

Preston Erickson

Preston Erickson

University: 

University of Utah

Major: 

Materials Science and Engineering

Site Abroad: 

Photonics Centre, Tyndall Institute, Cork, Ireland

Mentor(s): 

Emanuele Pelucchi

Faculty Sponsor(s): 

Agnieszka Gocalinska

Project Title: 

Optical Characterisation of Pyramidal Site-Controlled Quantum Dots by micro-Photoluminescence

Project Description: 

Quantum dots have attracted great interest as single photon sources for quantum key distribution and as possible sources of entangled photons. As this technology develops it is important to have a high degree of control over their fabrication. Quantum dots are grown by many different methods, mainly epitaxial (one layer at a time for maximum control). A lithography assisted metalorganic vapor phase epitaxy (MOVPE) technique allows quantum dots to be grown in inverted pyramidal recesses etched into a substrate during processing. This gives total control over where the pyramids form. The next step is controlling the properties of the dot by varying the composition of the dot and the geometry of the pyramids (by varying the etch time, etc. in the lithographic steps). This project focused on characterizing dots grown by this lithography assisted MOVPE technique to form a database of properties for III-V semiconductor quantum dots grown with different composition and deposition parameters. Micro-photoluminescence (µPL) was used as the characterization technique, which involved exciting the samples with a continuous wave laser and measuring the light which was reemitted. Many samples were measured and data was collected to detect such behavior as exciton and biexciton emission and fine structure splitting. This data will help future researchers tune the properties of new quantum dot structures to their specific needs and devices.