nz8b02346_si_001.pdf (377.81 kB)
Origin of Low Carrier Mobilities in Halide Perovskites
journal contribution
posted on 2019-01-11, 00:00 authored by Samuel Poncé, Martin Schlipf, Feliciano GiustinoHalide
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.