Electronic properties of Fe impurities in SnS van der Waals crystals – Revealing high-mobility holes

•Doping iron interacts with native defects in SnS.•Fe-doping reveals high hole mobility in SnS.•Carrier mobility is largely insensitive to the doping process and increasing mosaicity.•The dominant charge carrier scattering at higher temperatures is scattering on homopolar optical phonons. Defect control is critical to achieve long carrier lifetimes in semiconductors. SnS is a promising thermoelectric and photovoltaic material, in which native defects play a detrimental role, particularly in photovoltaics. In this study, we investigated the Fe-doping of SnS and the interaction of Fe impurities with native defects in a series of single crystals of Sn1-xFexS up to concentrations of x = 0.05. Although the doped single crystals appear rather disordered, the hole mobility is very high (∼8500 cm2V-1s−1 at 30 K for Sn0.99Fe0.01S), suggesting that hole-mediated charge transport in this material is largely insensitive to extrinsic impurities. Charge transport analysis suggests that the incorporation of Fe atoms leads to the healing of the intrinsic defect structure and the exclusion of minority electrons from charge transport, allowing the observation of high hole mobility.