Research groups around the world have recognized that perovskite is one of the most promising materials for the development of cheap, environmentally friendly and efficient solar cells. In just a few years, the power conversion efficiency has increased from a few percentage points to over 22%. However, at present, The perovskite-leader for solar cells, Feng Gao, a senior lecturer at Linkoping University, was appointed as a researcher at Wallenberg Institute in the fall of 2017 to develop lead-free dual perovskites using monovalent metals and trivalent metals instead of divalent lead.
The postdoctoral researchers Weihua Ning and Feng Wang of Linkoping University's Department of Biomolecular and Organic Electronics successfully created a double-layer perovskite dense crystalline monolayer film. These films are of very high quality and can be used as active layers in solar cells. , absorb sunlight in solar cells and generate charge carriers.
"Our colleagues at Nanyang Technological University in Singapore have shown that charge carriers exhibit long diffusion lengths in materials, which is a necessary condition for materials suitable for use in solar cells." Feng Gao said.
However, the power conversion efficiency of solar cells is still very low - only about 1% of solar energy is converted into electricity - Feng Gao and Weihua Ning are not worried.
'We have already taken the first step and developed a method for manufacturing an active layer. We have a few good ideas for how to increase efficiency in the near future.' said Feng Gao.
Weihua Ning also agreed with this statement.
Researchers have calculated that more than 4,000 different material combinations can form double perovskites. They will also use theoretical calculations to determine the most suitable combination for solar cells.
This breakthrough in double perovskite research is also a result of a joint Ph.D. program in materials and nanoscience/technology between Linkoping University and Nanyang Technological University.
'This paper is a by-product of the joint Ph.D. program of Nanyang Technological University and Linkoping University. Two Ph.D. students, each of whom were recruited to participate in this project, are a good start to the project.' said Professor Tze Chien Sum, Nanyang Technological University .
'We complement each other and the team led by professors at Nanyang Technological University is an expert in photophysics, and we are experts in materials science and device physics.' said Feng Gao.
The research results are published in the famous scientific journals' advanced materials.