Temperature dependent Current-Voltage characteristics show a 0.22 eV trap activation energy. (a) Temperature dependent measurements of the device current showing rectification with temperature. The current was measured at 1.25 V, which is above the turn-on voltage. At low temperatures the Poole-Frenkel current controls the current flow with a low activation energy while at high temperatures thermionic emission over a higher energy barrier controls current flow. (b) Plotting the Poole-Frenkel activation energy at a variety of applied voltages reveals a defect trap depth of 0.22 eV ± 0.01 eV matching the previously reported trap depth for oxygen vacancies in Nb2O5.