Seminarium Advanced Methods of Semiconductor Research – 25 listopada 2025
We cordially invite you to Advanced Methods of Semiconductor Research Seminar on Tuesday 25th of November 2025 at 13:15 in room 321, building A-1, where there will be delivered a lecture:
Morphology and spectroscopy of colloidal semiconductor quantum-dot thin films for application in modern optoelectronics
by Dr Maciej Chrzanowski
from Department of Experimental Physics, Wroclaw Tech
The lecture abstract is attached below.
—————————————————————————————————————-
Radiative decay rate of spontaneous emission in semiconductor nanostructures is strongly dependent on the dielectric environment, which is often neglected in literature concerning spectroscopy and applications of colloidal Quantum Dots (QDs) in thin-film optoelectronic devices, leading to misinterpretation of experimental data. Thin films of QDs are an example of an inhomogeneous structure, contrary to homogeneous QD dispersions in a solvent. The power dissipated by a dipole depends on this environment and is proportional to the local density of optical states (LDOS). This electromagnetic mode engineering can be theoretically reproduced by shaping boundary conditions during solving Maxwell’s equations, because classical electromagnetism can predict decay rate enhancement provided by a photonic system such as QDs thin film as compared to a reference system, e.g. a single QD on glass. Using this approach, the photoluminescence decay of nanoparticle ensemble deposited on a substrate can be correctly interpreted and explained in terms of film thickness, roughness, substrate refractive index, QDs packing density and symmetry.
In this talk, I will describe the theoretical approach which allows us to explain Time-Resolved Photoluminescence (TRPL) measurements of discontinuous and disordered multilayer films of QDs, as well as the structural characterisation methodology of those films, which involves Atomic Force Microscopy (AFM) as a tool to extract the boundary conditions which are necessary for numerical simulations. The obtained results provide a better understanding of thin-film QD layers formation and its impact on their optical properties, which is valuable for correct experimental data analysis in the process of optoelectronic devices optimisation.