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Short-Range Fringing Field-Driven Charge Separation in Mixed-Phase TiO2 Nanoparticles
Shan Pang1,2, Yang Liu1, Ruotian Chen1
1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy, Zhongshan Road 457, Dalian 116023, China.
None:
Combining near-coincidence-site lattice (NCSL) calculations and fringing-field simulations, we investigate the formation conditions and spatial vector distribution of the interfacial electric field at anatase/rutile phase junctions in TiO2 nanoparticles. Our analysis reveals that charge separation in these mixed-phase systems is governed not by the long-range built-in field of a classical depletion region, but by a strong, short-range fringing field localized at the phase boundary. The minority-carrier migration length defines an optimal phase-size combination of approximately 20 nm anatase and 6-13 nm rutile, within which the fringing-field strength exceeds 102 kV·cm-1. This work provides a quantitative design principle for enhancing charge separation efficiency through precise nanoscale phase engineering in mixed-phase photocatalysts and photovoltaic devices.
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