Ag-Doped Halide Perovskite Nanocrystals for Tunable Band Structure and Efficient Charge Transport

Heterovalent doping of halide perovskite nanocrystals (NCs), offering potential tunability in optical and electrical properties, remains a grand challenge. Here, we report for the first time a controlled doping of monovalent Ag+ into CsPbBr3 NCs via a facile room-temperature synthesis method. Our results suggest that Ag+ ions act as substitutional dopants to replace Pb2+ ions in the perovskite NCs, shifting the Fermi level down toward the valence band and in turn inducing a heavy p-type character. Field effect transistors fabricated with Ag+-doped CsPbBr3 NCs exhibit 3 orders of magnitude enhancement in hole mobility at room temperature, compared with undoped CsPbBr3 NCs. Low-temperature electrical studies further confirm the influence of Ag+ doping on the charge-carrier transport. This work demonstrates the tunability of heterovalent doping on the electrical properties of halide perovskite NCs, shedding light on their future applications in versatile optoelectronic devices.