Charge Carrier Accumulation in Lithium Fluoride Thin Films due to Li-Ion Absorption by Titania (100) Subsurface

The thermodynamically required redistribution of ions at given interfaces is being paid increased attention. The present investigation of the contact LiF/TiO2 offers a highly worthwhile example, as the redistribution processes can be predicted and verified. It consists in Li ion transfer from LiF into the space charge zones of TiO2. We not only can measure the resulting increase of lithium vacancy conductivity in LiF, we also observe a transition from n- to p-type conductivity in TiO2 in consistency with the generalized space charge model.