Recent Advances in Carrier-Resolved Photo-Hall Technology and its Application for World-Record Perovksites and Kesterites

Abstract

We report exciting advances in “carrier-resolved photo-Hall” technique that allow us to extract very rich information of both majority and minority carriers in electronics materials, such as carrier density, mobility, recombination lifetime and diffusion length. Our technique utilizes a new equation relating Hall mobility difference (ΔμH), Hall coefficient (H), and conductivity (σ): ΔμH = d($σ^2$H)/dσ, and employs a rotating parallel-dipole-line magnet system for a.c. field Hall measurement. We have successfully applied this technique to a range of solar absorbers, including CuZnSnSSe (CZTS) and lead-iodide-based perovskites, and added temperature-dependent measurement capabilities in the range of 20-340K to extract additional information about acceptor or donor levels and mobility scattering mechanisms. This progress brings a more complete understanding of how to probe charge carriers in electronic materials using the most common excitations in nature: electric field, magnetic fields, photons, and phonons or lattice vibration.