PNNL

Abstract

We have characterized thin films of LaScO3 and LaAIO3 which were grown by molecular beam deposition on Si substrates. Samples of LaScO3 were also grown by pulsed laser deposition of MgO substrates. Using transmission studies between 1.5 and 6 eV, we have established that low temperature deposition leads to a reduced band gap with respect to the bulk crystal. Furthermore, using spectroscopic ellipsometry form 5 to 9 eV we observe substantial difference in near-band gap absorption between thin and thicker films for both materials. We obtain a band gap of 5.84 eV for the thinner film of LaAIO3, shereas we find a band gap of 6.33 eV for the thicker film of LaAIO3. Similarly we find band gaps of 5.5 and 5.9 eV, respectively, for thin and thick films of LaScO3