| AVS 54th International Symposium | |
| Thin Film | Friday Sessions |
| Session TF2-FrM |
| Session: | Nanoparticles |
| Presenter: | D.L. Lahr, National Institute of Standards and Technology |
| Authors: | D.L. Lahr, National Institute of Standards and Technology J.K. Evju, National Institute of Standards and Technology K.B. Benkstein, National Institute of Standards and Technology J.L. Hertz, National Institute of Standards and Technology S. Semancik, National Institute of Standards and Technology |
| Correspondent: | Click to Email |
Tin(IV) oxide (SnO2) has been studied extensively as a chemiresistive sensing material. Increasingly, it has been shown that morphologies of SnO2 with nanoscale dimensions have improved sensing properties compared to the bulk material. We report on the observation of chemical states of tin present at the surfaces of a variety of nanoscale SnOx materials using X-ray Photoelectron Spectroscopy (XPS). Nanoparticles, nanowires and nanostructured thin films with a nominal stoichiometry of SnO2 actually contain a range of oxidation states of tin, from tin(IV) to tin(0), at their surfaces. Depth profiling reveals the underlying tin(IV) oxide in each of these materials, and provides information on the relative amounts of the various chemical states present as a function of depth. In addition, we present methods to control the extent of oxidation of these materials, as monitored by XPS. We propose that the relative amounts of the chemical states of tin at the surfaces of sensors composed of these materials influence their sensitivity and stability. Control of the composition of the chemical states of tin can lead to improved sensor performance.