Adaptation of the Solar Spectrum to Improve the use of Sunlight: A Critical Review on Techniques, Applications, and Current Trends

Photovoltaic (PV) cells are one of the most common devices to harvest solar radiation and convert it into usable electrical power. However, normal silicone-based photovoltaic cells work best within the visible light region. Conventional PV panels can use 15-30% of the total energy received, while the remainder is reflected or converted into waste heat. Not only do other wavelengths have lower conversion efficiencies, but they may also increase the cell surface temperature and decrease its overall efficiency. To solve this problem, spectral beam splitting is a potential approach for converting solar energy efficiently. Even though spectral-splitting systems have high theoretical conversion efficiencies, they have not yet reached the commercial level. The current study describes the advancements in beam-splitting systems based on thermal PV cells, multijunction cells, nano-film, conventional, and nanofluids over the last decade. The mechanisms of various splitting system techniques and several hybrid applications are thoroughly discussed in order to provide a comprehensive understanding of solar energy utilization and the considerations influencing system efficiency. Even though the cost increase can be offset by the increased energy conversion efficiency and controlled wavelengths, the system's stability must be addressed for future practical applications.