MRS Meetings and Events

 

QT01.11.04 2023 MRS Fall Meeting

Excitonic Behavior in Perovskite Nanoplatelets—The Role of Defects and Achieving Linearly Polarized Electroluminescence

When and Where

Dec 7, 2023
9:30am - 10:00am

QT01-virtual

Presenter

Co-Author(s)

Robert Hoye1

University of Oxford1

Abstract

Robert Hoye1

University of Oxford1
Linearly polarized light is important for a wide range of applications, such as 3D displays and optical communications. However, linear polarization is typically achieved by filtering unpolarized light, which leads to significant losses in energy. This talk examines the use of nanostructured lead-halide perovskites to directly achieve polarized light emission.<br/><br/>Although nanostructured halide perovskites have important advantages in terms of color purity and tunability, they are strongly affected by surface defects. Thus, the first half of this talk examines how the surface chemistry of CsPb(Br<sub>x</sub>I<sub>3-x</sub>) nanocrystals can be controlled through the polarity of the antisolvent used during purification. Through detailed nuclear magnetic resonance, Fourier transform infrared spectroscopy and X-ray photoemission spectroscopy measurements, we show that higher polarity antisolvents lead to increased selective etching of the iodide species due to the removal of the long-chain organic ligands through condensation reactions [1].<br/><br/>The second half of the talk discusses the use of self-assembled CsPbI<sub>3</sub> perovskite nanoplatelets to achieve polarized light emission. We show that the high dielectric and quantum confinement in these nanoplatelets leads to a large splitting in the exciton fine structure. In the edge-up perovskite nanoplatelet superlattices, we achieve strong emission from the out-of-plane dipole for the optically bright excitons. In light-emitting diodes, this led to a high degree of polarization in electroluminescence of 74.4% without requiring the use of any photonic structures [2].<br/><br/>[1] Ye, …, Hoye, J. Am. Chem. Soc., 2022, 144, 12102<br/>[2] Ye, …, Hoye, arxiv: 2302.03582

Keywords

defects | perovskites

Symposium Organizers

Sudeshna Chattopadhyay, Indian Institute of Technology Indore
Yara Galvão Gobato,
Ursula Wurstbauer, Technical University of Munich
Shouvik Datta, IISER-Pune

Publishing Alliance

MRS publishes with Springer Nature