| AVS 59th Annual International Symposium and Exhibition | |
| Applied Surface Science | Monday Sessions |
| Session AS-MoM |
| Session: | Quantitative Surface Chemical Analysis, Technique Development, and Data Interpretation - Part 1 |
| Presenter: | A.E. Wright, Thermo Fisher Scientific, UK |
| Authors: | A.E. Wright, Thermo Fisher Scientific, UK P. Mack, Thermo Fisher Scientific, UK R.G. White, Thermo Fisher Scientific, UK A. Bushell, Thermo Fisher Scientific, UK |
| Correspondent: | Click to Email |
Optoelectronic devices, used for inter-conversion of light and electricity (e.g. photovoltaics and displayes), depend upon careful optimisation of chemical, electronic and structural properties for efficient operation and useful operating lifetime.
Characterisation of such a device will typically identify the chemical bonding states, valence band positions, band gap and work function for each component. Lateral and depth resolution may be required to evaluate cell/pixel and multilayer structures.
Electron spectroscopic surface analysis techniques are ideal for the detailed analysis of the electronic structures of optoelectronic devices. Such techniques allow full quantitative characterisation of materials with chemical state and structural information. Surface specificity of spectroscopic information ensures that thin films can be analysed without interference from deeper parts of the sample. Multilayer structures may be studied with depth profiling techniques, and imaging functionality may be used to study cell or pixel structures.
The Thermo Scientific Escalab250Xi offers several such spectroscopic techniques, which have been employed in this study. X-ray Photoelectron Spectroscopy (XPS) offers surface-sensitive, quantified chemical state analysis and imaging capabilities. Ultraviolet Photoelectron Spectroscopy (UPS) allows measurement of valence band positions. Reflected Electron Energy Loss Spectroscopy (REELS) yields information on the electronic band gap and hydrogen content of a material. These techniques are combined for a thorough characterisation of the electronic structure of optoelectronic devices.