[18p-P02-1~30] 6.3 Oxide electronics

[18p-P02-24] A new method for evaluating surface electronic energy of α-Fe₂O₃ particles dispersed in aqueous solution: an approach using photoemission yield spectroscopy in air.

〇Mariko Kinoshita¹, Sayaka Yanagida¹, Shoichi Somekawa¹, Syouhan Yanagi¹, Satoshi Kuwahara¹ (1.TIRI)

Keywords:

photoemission spectroscopy,hematite,surface electronic states

In aqueous solutions, the surface of solid undergoes dissociation of surface functional groups and molecular adsorption of solutes, leading to the changes in the surface potential of the solid. In the case of surface of a semiconductor, the energies of the valence band maximum (E_V) and the conduction band minimum (E_C) shift along with the change in surface potential. Semiconductor particles dispersed in aqueous solution can be utilized as photocatalyst for the water splitting and the water purification. The change in the surface potential of the semiconductor should affect the photocatalytic activity because oxidizing ability is related with E_V and reducing ability is related with E_C. However, shifted E_V and E_C cannot be evaluated if the semiconductor particles are not connected to an electric circuit. In this study, we developed a new method to evaluate the E_V of semiconductor particles dispersed in aqueous solution using the photoemission yield spectroscopy in air.