Accelerator-based nuclear techniques for processing and characterization of oxide semiconductors for solar energy conversion

Accelerator-based nuclear techniques are an important tool for the modification and characterization of surfaces in general, down to a depth of around one micrometer. For oxide semiconductors used in solar energy conversion, the surface plays a critical role in facilitating the use of solar photon energy to obtain hydrogen via spontaneous water oxidation. For such a process, the required surface properties are complex and include specific chemical composition, as well as the defect composition, and both of these characteristics may be augmented using accelerator-based nuclear techniques. The targeted modification of surfaces makes use of ion implantation for changing the chemical composition, and ion irradiation for changing the defect structure. The defect formation is a very complex process, and in this work we placed more emphasis on this aspect. We attempted to present the defect formation under the irradiation of ion beams at the two extremes: Formation of extensive and large-scale cluster defects; and formation of small-scale point defects. In addition, we review the main characterization techniques based on ion beams, with examples from work carried out on semiconductors and oxide semiconductors.