Dynamic lattice distortions driven by surface trapping in semiconductor nanocrystals
Abstract
Nonradiative processes limit optoelectronic functionality of nanocrystals and curb their device performance. Nevertheless, the dynamic structural origins of nonradiative relaxations in nanocrystals are not understood. Here, femtosecond electron diffraction measurements corroborated by atomistic simulations uncover transient lattice deformations accompanying radiationless electronic processes in semiconductor nanocrystals. Investigation of the excitation energy dependence shows that hot carriers created by a photon energy considerably larger than the bandgap induce structural distortions at nanocrystal surfaces on few picosecond timescales associated with the localization of trapped holes. On the other hand, carriers created by a photon energy close to the bandgap result in transient lattice heating that occurs on a much longer 200 ps timescale, governed by an Auger heating mechanism. Elucidation of the structural deformations associated with the surface trapping of hot holes provides atomic-scale insights into the mechanisms deteriorating optoelectronic performance and a pathway towards minimizing these losses in nanocrystal devices.
Cite
@article{arxiv.2101.01586,
title = {Dynamic lattice distortions driven by surface trapping in semiconductor nanocrystals},
author = {Burak Guzelturk and Benjamin L. Cotts and Dipti Jasrasaria and John P. Philbin and David A. Hanifi and Brent A. Koscher and Arunima D. Balan and Ethan Curling and Marc Zajac and Suji Park and Nuri Yazdani and Clara Nyby and Vladislav Kamysbayev and Stefan Fischer and Zach Nett and Xiaozhe Shen and Michael E. Kozina and Ming-Fu Lin and Alexander H. Reid and Stephen P. Weathersby and Richard D. Schaller and Vanessa Wood and Xijie Wang and Jennifer A. Dionne and Dmitri V. Talapin and A. Paul Alivisatos and Alberto Salleo and Eran Rabani and Aaron M. Lindenberg},
journal= {arXiv preprint arXiv:2101.01586},
year = {2021}
}
Comments
17 pages, 4 figures