Abstract
Conductive rutile TiO2 has received considerable attention recently due to multiple applications. However, the permittivity in conductive, reduced or doped TiO2 appears to cause controversy with reported values in the range 100–10,000. In this work, we propose a method for measurements of the permittivity in conductive, n-type TiO2 that involves: (i) hydrogen ion-implantation to form a donor concentration peak at a known depth, and (ii) capacitance–voltage measurements for donor profiling. We cannot confirm the claims stating an extremely high permittivity of single crystalline TiO2. On the contrary, the permittivity of conductive, reduced single crystalline TiO2 is similar to that of insulating TiO2 established previously, with a Curie–Weiss type temperature dependence and the values in the range 160–240 along with the c-axis.
Highlights
Conductive rutile TiO2 has received considerable attention recently due to multiple applications
Similar values of (1 − 3) × 104 were later observed by Parker and Wasilik[2] for single crystalline rutile TiO2
We have demonstrated p reviously[14,15] that annealing of single-crystalline T iO2 wafers in N 2 at 1100–1200 °C or in forming gas (FG), 10%at
Summary
Conductive rutile TiO2 has received considerable attention recently due to multiple applications. The permittivity in conductive, reduced or doped TiO2 appears to cause controversy with reported values in the range 100–10,000. The permittivity of conductive, reduced single crystalline TiO2 is similar to that of insulating TiO2 established previously, with a Curie–Weiss type temperature dependence and the values in the range 160–240 along with the c-axis. Similar values of (1 − 3) × 104 were later observed by Parker and Wasilik[2] for single crystalline rutile TiO2. Parker and Wasilik[2] suggested that, in the case of non-negligible free carrier concentration, i.e., non-negligible effective net doping, Schottky contacts can be unintentionally formed (see Supplementary Material for a description of the Schottky contact) This is relevant in the case of reduced TiO2, where oxygen vacancies give rise to n-type doping.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
