Twisted perovskites - control of spin and chirality in highly-luminescent metal-halide perovskites
The translation of chirality from molecular to bulk inorganic systems opens many possibilities for new phenomena. The properties of chiral electronic states are interesting scientifically and attractive for applications. While optoelectronic properties of semiconductors are controlled by charge, magnetic materials function by spin. If a material can combine these functionalities, powerful novel applications and large gains in performance are possible in opto-spintronics. Yet, existing magnetic semiconductors often show lower optoelectronic quality or work at low temperature. Development of new systems is a scientific challenge due to the required coordination of spins and control of physical properties of excited states, while minimizing defects.

TWIST will demonstrate novel highly-luminescent semiconductors for spin-control and chiral emission that show combined properties of ferromagnets and excellent semiconductors for efficient spin-LEDs at room temperature. To achieve this, TWIST will develop new approaches to control spin and chirality in doped metal-halide perovskites (MHPs) with magnetic elements and molecules, also in chiral superstructures.

In 2014, I reported that MHPs are exceptionally bright emitters, which underpins their tolerance to defects and chemical variation, and which recently enabled remarkable doping with transition-metals. Optical spin-control and chiral emission are possible from spin-orbit coupling and Rashba effects, which will enhance spin-order for Curie temperatures towards room temperature. These exceptional properties of MHPs, which have already produced efficient solar cells and LEDs, provide now a unique opportunity for my project.

TWIST will use state-of-the art optical and electronic techniques to unravel the fundamental mechanisms how magnetic moments, light and chiral states order and interact in MHPs. The results of TWIST will instigate opto-spintronic applications with novel functionality and lower energy consumption.