Doctoral position in experimental characterization of semiconductor nanocrystals

The doctoral student will characterize semiconductor nanocrystals using complementary optical and structural experimental techniques. The initial focus will be on CdSe magic-sized nanocrystals, with the work subsequently expanding to nanocrystals of different sizes, compositions, surface treatments, and heterostructures, including core/shell and InP nanocrystals. The project will investigate how variations in nanocrystal size, shape, composition, surface chemistry, and structure influence optical properties. Ensemble and single-particle spectroscopy will be used to quantify optical heterogeneity and determine how closely magic-sized nanocrystals approach atomic-scale perfection. Measurements will examine properties such as emission linewidths, excited-state dynamics, spectral fluctuations, and the suitability of selected nanocrystals as single-photon emitters. These optical studies will be complemented by advanced structural characterization. In particular, the student will use cryogenic electron microscopy and single-particle analysis to determine the three-dimensional structures of semiconductor nanocrystals with near-atomic or atomic-scale resolution. The experiments will examine nanocrystal shape, including the possible truncation of tetrahedral magic-sized nanocrystals, and how it varies with particle size, material composition, surface treatment, and isolation procedure. The doctoral student will work closely with researchers responsible for nanocrystal synthesis and theoretical modeling. This interaction is central to the project: advanced samples will be supplied for optical and structural measurements, while the characterization results will guide improvements in nanocrystal synthesis, surface treatment, and structural control. The experiments will use the laboratory’s optical microscopy and spectroscopy infrastructure as well as the state-of-the-art electron microscopy facilities available at ETH Zurich. In addition to research, the doctoral candidate will contribute to general laboratory activities and will have opportunities to participate in teaching and the supervision of bachelor’s and master’s students.

The Optical Materials Engineering Laboratory (Prof. David J. Norris) in the Department of Mechanical and Process Engineering (D-MAVT) at ETH Zurich investigates the synthesis, growth, structure, and optical properties of nanomaterials. Our interdisciplinary and international team combines materials chemistry, optical spectroscopy, electron microscopy, theoretical modeling, and numerical simulation to understand and control materials at the nanoscale.

• Applicants must hold, or be close to completing, an MSc degree in chemistry, chemical engineering, materials science, mechanical engineering, nanoscience, physics, or a closely related discipline.

• Experience in one or more of the following areas would be advantageous: Optical spectroscopy or microscopy, Time-resolved or single-particle measurements, Electron microscopy, Image processing, three-dimensional reconstruction, or single-particle analysis, Semiconductor nanocrystals, quantum dots, or other nanoscale materials, Machine learning, Scientific programming and quantitative data analysis.

• Prior experience with every technique used in the project is not required.

• The successful candidate should, however, have a strong experimental and quantitative foundation and an enthusiasm for learning new optical and structural characterization methods.

• Academic excellence, a professional approach to research, careful laboratory practice, and the ability to work independently are expected.

• The candidate must be able to communicate fluently in English, both orally and in writing, and should enjoy working in a collaborative and international research environment.