Interaction of cesium with charged oxide under UV irradiation imaged by photoemission electron microscopy

We report the first observation of electron transfer from charged SiO₂/Si(1 0 0) by ion-implantation via internal photoemission from Si by photoemission electron microscopy (PEEM) for the purpose of the microscopic control of promotion of catalyst by electron transfer from oxide support. The contrast of the PEEM image varies with the amount and kind of the implanted ion and the deposition of Cs through the formation of electrical double layer consisting of Cs⁺ and trapped electrons at trapping centers created by the implantation. It is then firmly established that oxide charging can be microscopically tuned by ion-implantation.