PHI Webinar Series: Electronic Band Structure Characterization using LEIPS & UPS XP

The development of complex materials for batteries, solar cells, and flexible display panels requires a detailed knowledge of the electronic band structure in order to achieve desired performance. A few of the material properties of interest are electron affinity, work function, ionization potential, and band gap. Traditionally, measurement of these properties has required the use of multiple analytical instruments, making it difficult to characterize the same location on a sample and avoid contamination due to multiple sample transfers.
Low energy inverse photoemission spectroscopy (LEIPS) is a new option on the VersaProbe III Multi-Technique XPS system for analysis of the unoccupied electronic states (conduction band) of a material, allowing direct measurement of the electron affinity. For organic electronic materials, a major advantage of LEIPS compared to traditional inverse photoemission spectroscopy (IPES) methods is the low incident energy of probe electrons. This minimizes chemical damage to the sample and provides greater confidence when measuring electron affinity.
LEIPS is a complementary tool to ultraviolet photoelectron spectroscopy (UPS), commonly used for evaluation of the occupied electronic states (valence band) and provides work function and ionization potential. With both techniques, the band gap can be determined. As shown in Figure 1, the combination of UPS and LEIPS gives a complete picture of the electronic band structure.
In this webinar, the principles of LEIPS and UPS will be discussed. Several examples of band structure analysis will be demonstrated on organic photovoltaic materials. Additionally, these techniques can be combined with other options on the VersaProbe, such as XPS and gas cluster ion beam sputter depth profiling, for comprehensive characterization of surfaces and interfaces.

[@suaaap7701]

surely one of the best explanation of UPS application, thank you very much!

[@abduhebermirzehmet9514]

Thank You Very Much!!!!

[@user-xe4gk1kw3b]

Very interesting presentation and comprehensive explanation! But on some graphs there are no values on the y axis. It will be interesting what counts did you get on these samples...

[@alexcao242]

In my experiment, even if no bias is used, the cutoff edge can also be measured. so why you not directly measure the spectra above 17eV in UPS to directly obtain the Ef?