Prof. Hilmi Volkan Demir, director of UNAM and faculty member in the Department of Electrical and Electronics Engineering, the Department of Physics, and the Materials Science and Nanotechnology Graduate Program, and his research team have published a scientific article on “Observation of Phonon Cascades in Cu-Doped Colloidal Quantum Wells”, which is highlighted on the cover of Nano Letters.
Electronic doping can endow atomically-flat semiconductor nanocrystals commonly referred to as colloidal quantum wells (CQWs) with unique optical and electronic properties stemming from their 2D structure, which holds great potential for future developments in optoelectronic devices. Unfortunately, how photogenerated “hot” carriers (high-energy charges) in these doped CQWs interact with the vibrations of their host crystal (phonons) still remains an open question. The team’s study investigated the emission properties of Cu-doped CQWs allowing for the observation of an efficient phonon cascade process and identifying a giant Huang−Rhys factor (S ≈ 12.4). This study also found that coupling in such Cu-doped CQWs is due to dopant-induced crystal lattice distortion and the dopant-enhanced density of electronic states. The findings of this work will find use in making high-performance optoelectronic devices.
You can access the study at the following link: https://pubs.acs.org/doi/full/10.1021/acs.nanolett.2c03427https://onlinelibrary.wiley.com/doi/10.1002/admi.202201126
