Postdoc and Graduate Student Opportunities

Graduate Student and Postdoc Opportunites in Research on Hybrid Organic-Inorganic Perovksite

contact Mike (mftoney@slac.stanford.edu) for details

The Toney research group at the SLAC National Accelerator Laboratory seeks graduate students or postdocs for research into the foundation materials physics and chemistry of hybrid metal halide perovskite semiconductors (HPSCs). These positions involve research 1) understanding the lattice dynamics of HPSCs and their impact on optoelectronic properties and 2) understanding and quantifying defects and ion diffusion.

Two of the distinguishing properties of HPSCs that sets them apart from conventional semiconductors is the dynamical disorder present in the lattice and the propensity to form defects, largely halide vacancies. These phenomena have tremendous impact of the HPSC performance as the lattice dynamics is important in the cooling and transport of photoexcited charges (i.e., electron-phonon coupling) and point defects facilitate ion motion, which strongly impacts instability.

One open position involves using inelastic neutron scattering (INS) to investigate the lattice dynamics of perovskites as a function of composition and temperature. The goal is to understand how these compositional variation affect performance by understanding the impact of lattice dynamics on carrier dynamics.

The other position involves quantifying the defect nature as a function of perovskite composition and formation process. This includes micro phase separation – at what length scale does an alloy become inhomogeneous – as this impacts performance and stability. Compositional fluctuations can lead to nucleation sites for photo-induced compositional instabilities. The absolute halide vacancy concentration and its dependence on processing can be determined with a novel analysis methodology.