With the global climate change, the continuous consumption of non-renewable energy and the improvement of human requirements for environmental protection, the concept of carbon emission has gradually become popular. One of the main ways to reduce carbon emissions is to use clean energy, among which solar energy is a kind of renewable clean energy that can be widely used. Based on the basic principle of solar cells and through the classification of solar cell materials, this paper introduces the research status of solar cells prepared by the first generation semiconductor silicon and the third generation semiconductor InGaN/GaN, and summarizes the main optimization methods and principles of solar cell efficiency. Silicon nanowire solar cells are rich in raw materials and easy to be prepared. They are the most widely used solar cells at present, but their efficiency is low and needs to be improved. The main method is to optimize their nanowire structure and material surface properties. InGaN/GaN nanowire solar cells can improve their photoelectric conversion efficiency by adjusting the In component, which is also the direction of improving the efficiency of the third generation semiconductor solar cells. Finally, the future development direction is proposed, which can provide the direction and basis for the efficiency optimization of nanowire solar cells.