Borate

Presently, the realization of energy necessity of human beings is at great task. Also, the clean and immaculate resources have colossal demand in this field. With the rationale of the long haul demand of energy solar energy has become the most promising energy resource because of its advantages of being inexhaustible and pollution free. The capacity of photovoltaic (PV) devices (based on silicon solar cells) to convert sunlight into electricity make them prime candidates for this task. However, the spectral mismatch that is accountable for the thermalization of charge carriers generated by the absorption of high-energy photons reduces the conversion efficiency of solar cells. The diminution in cost may be achieved by either lowering the production cost or by improving the performance and PV conversion efficiency. The commercial crystalline silicon (c-Si) solar cells dominate the PV technology market and have efficiency around 15%. This chapter covers the ideas of luminescence process, such as up-conversion (UC) down-conversion (DC) and downshifting (DS), which are useful to get spectral modification so that spectral mismatch can be minimized. Rare earth (RE) doped borates and some orthoborates generally have a high degree of ultraviolet (UV) transparency and excellent optical damage threshold, which causes them to be prime candidates for various practical applications. There are very few attempts to explore borate-based phosphors as candidates for UC, DC and DS phosphors to achieve spectral modification c-Si solar cells. It is shown that borate-based phosphors are useful to achieve spectral modification for c-Si solar cells via (DS) luminescence processes which could also be useful in satellite applications.