| AVS 64th International Symposium & Exhibition | |
| Thin Films Division | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Jason Creeden, The College of William and Mary |
| Authors: | J. Creeden, The College of William and Mary I. Novikova, The College of William and Mary R.A. Lukaszew, The College of William and Mary |
| Correspondent: | Click to Email |
The goal of this project is to optimize the efficiency of the optically induced insulator to metal transition (IMT) in the near-UV and UV regions, following the recent demonstration that VO2 prepared on niobium doped TiO2 (TiO2:Nb) substrates can push the photoconductive response, ordinarily strong in the infrared, into the visible spectrum. Therefore, this project focused on the tailoring of the optical and microstructural parameters pertaining to the IMT in VO2 thin films. This was done by controlling the microstructure of the films via deposition parameters and substrate doping and thus optimizing the VO2 growth process for TiO2 and TiO2:Nb substrates. In doing so, we strained the monoclinic structure seen in the insulating phase toward the tetragonal structure seen in the metallic phase post-transition. The film composition was characterized via X-ray diffraction (XRD) and changes to the VO2 optical transmissions, during the thermally induced IMT, were recorded using both a HeNe laser (1520 nm) and a 405 nm diode laser. With the HeNe laser, we could see strained bulk-like transitions of VO2 occurring for samples grown on TiO2 and small transitions for the samples grown TiO2:Nb. The samples grown on TiO2:Nb structurally exhibit a .25o shift in the XRD peak location in comparison to the un-doped samples. With the 405 nm laser, the samples grown on TiO2:Nb exhibit sharp transitions that are comparatively large to those of the slight transitions seen in samples grown on TiO2. Suggesting that the doping enhances the near-UV optical response of the film.