John Stewart Preston

John Stewart Preston is a Professor in the Department of Engineering Physics at McMaster University's Faculty of Engineering. His research focuses on advanced materials development using laser-based techniques, with particular emphasis on photovoltaic applications. He directs the NSERC CREATE Program in Photovoltaics and utilizes world-class facilities including the Brockhouse Materials Research Institute, Canadian Centre for Electron Microscopy, and McMaster Analytical X-Ray Facility.

Professor Preston's research spans three primary areas: Pulsed Laser Deposition (operating three specialized chambers for thin film deposition), Self-Assembly of Epitaxial Nanostructures (investigating gold on spinel crystals and CdTe nanostructures on sapphire), and Photovoltaics (developing novel enhancements to silicon solar cells, II-VI solar cells, and hybrid organic-inorganic cells). His work demonstrates an evolution from fundamental laser-material interactions to practical photovoltaic applications, with recent research focusing on interface engineering, epitaxial growth mechanisms, and advanced characterization of semiconductor materials.

His publication record shows consistent contributions to materials science, with recent work emphasizing heteroepitaxial growth, interface characterization, and photovoltaic material development. The research demonstrates strong interdisciplinary connections between materials science, nanotechnology, and renewable energy applications, with significant focus on crystal growth mechanisms and interface phenomena.

Professor Preston teaches several courses including Engineering: Communications and Social Impact (ENGINEER 2PX3), Professional Communication and Project Management (ENGPHYS 3EC4), and Principles of Solid-state Materials and Devices (ENGPHYS 3F03). His research group operates specialized laser deposition facilities and collaborates extensively with McMaster's advanced materials characterization centers.

His laboratory work involves three pulsed laser deposition chambers (optimized for pure materials, large area deposition, and oxygen-sensitive materials) and leverages McMaster's world-class electron microscopy and x-ray facilities for comprehensive materials characterization. Recent research directions include developing new material systems for exceptional photovoltaic performance and exploring the self-assembly of nanoscale structures driven by strain and surface tension.