Nowadays, it is necessary to find a new energy conversion method to solve the energy crisis. Environmental pollution is another critical problem which needs to be solved. In addition, solar energy is a clean, abundant, reproducible energy source in the world. Photoelectrochemical fuel cell (PEC) is an energy conversion and pollutant-clean system using solar energy. The significant characteristics of PEC are the generation of electric energy, the splitting of the water, and degraded contaminative solutions. Nowadays, the PEC field is still short of intensive research because this is an interdiscipline which includes physics, chemistry, electrology, and mechanics. The efficiency of the PEC is still too low in terms of the practical application in industry. With the nano technology's development, researchers found that nano-structured photovoltaic materials can enhance the performance of PEC. There are multiple choices of materials which can be SiO, GaAs、GaAlAs、InP、CdS、CdTe, etc. Researchers are focusing on choices and fabrications of materials.