[Abstract]

Metal halide perovskite optoelectronic devices have made significant progressover the past few years, but precise control of charge carrier density throughdoping is essential for optimizing these devices. In this study, the potential ofusing an organic salt, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, as a dopant for Sn-based perovskitedevices, is explored. Under optimized conditions, the thin film transistorsbased on the doped 2D/3D perovskite PEAFASnI₃ demonstrate remarkableimprovement in hole mobility, reaching 7.45 cm² V⁻¹ s⁻¹ with a lowsubthreshold swing and the smallest sweep hysteresis (????V hysteresis = 2.27 V)and exceptional bias stability with the lowest contact resistance (2.2 k???? cm).The bulky chemical structure of the dopant prevents it from penetrating theperovskite lattice and also surface passivation against Sn oxidation due to itshydrophobic nature surface. This improvement is attributed to thebifunctional effect of the dopant, which simultaneously passivates defects andimproves crystal orientation. These findings provide new insights intopotential molecular dopants that can be used in metal halide perovskitedevices.