Scientists from Nanyang Technological University, Singapore in collaboration with the University of Groningen have developed a method to analyse which pairs of materials in perovskite solar cells will harvest the most energy.
In a paper published in Science Advances, physicists Professor Sum Tze Chien from NTU and Professor Maxim Pshenichnikov from UG used lasers to observe how an energy barrier forms when perovskite is joined with a material that extracts the electrical charges to make a solar cell.
When a solar cell absorbs sunlight and converts it to electrical charge, the light particles have more energy than needed to generate electrical charges. This excess energy results in “hot” charges, which lose their excess energy very fast as heat, leaving only “cold” charges available for electrical power generation.
Prof Sum, the Associate Chair (Research) at NTU’s School of Physical and Mathematical Sciences, said “Our latest findings show how ‘hot’ these charges have to be, in order to cross over the energy barrier without being wasted as heat. This highlights the need for better pairing of ‘extraction’ materials with perovskites if we want to lower this energy barrier for more efficient solar cells.”