Sb$_{x}$O$_{y}$ thin films using pulsed lased deposition

We demonstrate synthesis of Sb$_{2}$O$_{3}$ and Sb$_{2}$O$_{4}$ thin films on heated glass, and fused SiO$_{2}$ slides in an oxygen atmosphere using pulsed laser deposition and ex-situ annealing in air. GW calculations with spin-orbit corrections predict that the band gap of Sb$_{2}$O$_{3}$ changes from 3.4 eV in the orthorhombic $\beta $-phase to 4.7 eV in the cubic $\alpha $-phase. Sb$_{2}$O$_{4}$ also forms two polymorphic structures, orthorhombic $\alpha $-Sb$_{2}$O$_{4}$, and monoclinic $\beta $-Sb$_{2}$O$_{4}$. Optical absorption and crystal structure are investigated using transmission/reflection spectroscopy and grazing incidence x-ray diffraction. Optical absorption measurements of $\alpha $-Sb$_{2}$O$_{4}$ show a band gap of 3.9 eV which is far from the DFT predicted band gap of 2.1 eV but agrees with previous measurements. Structural analysis shows that from an $\alpha $-Sb$_{2}$O$_{4}$ target, $\alpha $- Sb-$_{2}$O$_{4}$ thin films are formed at a temperature and pressure of 400 $^{\circ}$C and 3 mTorr. Deposition at higher pressures (6 and 12 mTorr) produces amorphous films that, when annealed at 500 $^{\circ}$C become a mixture of $\alpha $-Sb$_{2}$O$_{4}$ and an additional cubic phase of Sb$_{2}$O$_{4}$.