New method to create efficient perovskite solar cells

• Scientists from Singapore and Netherlands have found out how to create highly-efficient next-generation solar cells of perovskite materials.

The scientific groups from universities of Groningen and Nanyang have discovered how to select the most efficient pairs of materials for advanced perovskite photovoltaic cells. With the help of superfast lasers, they examined the way an energy barrier gets formed when perovskites contact the charge extracting layer. 

Traditional photovoltaic cells collect light of the sun to transform it into electric energy. However, photons carry more energy than required for electricity generation. This excessive energy produces ‘hot’ charge carriers. They waste excessive energy very quickly, as a result only ‘cold’ charges remain available to generate electrical power. 

Due to this energy loss phenomenon, the efficiency of commonly used PV cells cannot exceed 33 percent. The most advanced perovskite-base cells show 25-percent performance – almost as efficient as the best silicon devices. What sets perovskite cells apart from conventional silicon cells is simple and inexpensive production technology.

In order to harvest hot electrons fast, the proper charge extracting material is to be selected. The research group has created a method to choose the best extraction material. 

They have found out how ‘hot’ the charge has to be for overcoming the energy barrier and not being wasted. In order to minimize the barrier and improve conversion efficiency, the extraction material has to be selected more carefully.