Physics

Electron

Crystallography

Electron mobility

Semiconductor

Hexagonal crystal system

Chemical physics

Halide

Inorganic chemistry

Chemistry

Materials science

Phonon

Condensed matter physics

Quantum mechanics

Diode

Wurtzite crystal structure

Optoelectronics

ACS Energy Letters

Halide perovskites constitute a new class of semiconductors that hold promise for low-cost solar cells and optoelectronics. One key property of these materials is the electron mobility, which determines the average electron speed due to a driving electric field. Here we elucidate the atomic-scale mechanisms and theoretical limits of carrier mobilities in halide perovskites by performing a comparative analysis of the archetypal compound CH3NH3PbI3, its inorganic counterpart CsPbI3, and a classic semiconductor for light-emitting diodes, wurtzite GaN, using cutting-edge many-body ab initio calculations. We demonstrate that low-energy longitudinal-optical phonons associated with fluctuations of the Pb–I bonds ultimately limit the mobility to 80 cm2/(V s) at room temperature. By extending our analysis to a broad class of compounds, we identify a universal scaling law for the carrier mobility in halide perovskites, and we establish the design principles to realize high-mobility materials.

Origin of Low Carrier Mobilities in Halide Perovskites