The current global energy crisis has led to an urgent need to reduce dependence on non-renewable energy. Solar energy is one of the best strategies for sustainable energy production. Xi’an Jiaotong-Liverpool researchers used new innovation to improve solar cells.
Solar panels are made up of photovoltaic (PV) cells, which capture photon energy from sunlight to generate electricity. However, this method does not work now and a lot of energy is lost during conversion. Optimizing the photovoltaic conversion efficiency (PCE) of photovoltaic cells has become the focus of solar energy research.
In a recent study, researchers from Xi’an Jiaotong-Liverpool University and other universities in China and the UK used a new substance, MXene, to improve performance of photovoltaic cells. Researchers used new innovation to improve solar cells. The use of photovoltaic cells is important to ensure maximum efficiency in the conversion of solar energy to electricity, with significant progress in recent years.
In 2009, photovoltaic cells made from synthetic materials called perovskites – instead of the usual silicon – were introduced and have since been the subject of research and investment. “Perovskite solar cells offer a cheap and flexible alternative to silicon, and over the past decade, the efficiency of converting sunlight into electrical energy in these cells has improved.
However, stability of perovskite cells remains a key issue for commercialization,” explains Li Yin, lead author of the study and a doctoral student at the School of Advanced Technology. “In our study, we improved the efficiency of perovskite solar cells and achieved conversion efficiency close to the highest efficiency record (25.7%). Our cells also have excellent water resistance and operational stability.
Move through the layers
Photovoltaic cells are composed of several layers of different materials. When a PV cell receives energy from sunlight, the energy is transferred to negative charges (electrons) in the surface layer. This causes electrons to pass through the electron transfer layer to the positive electrode. This movement creates electricity.
The research team added a newly discovered material called MXenes to the electron transport layer to allow electrons to pass between them more efficiently. This improved the conversion of sunlight to electrical energy in perovskite cells and, therefore, efficiency.
“For perovskite solar cells, choosing the right materials to make the electron transport layer efficient and suitable is crucial to achieve high stability and conversion efficiency,” Yin says. “At first, we added non-volatile MXene to the electrical layer, which did not have much effect. However, when we discussed with Dr. Chenguang Liu and Dr. Chun Zhao, the other authors of the report words, we understand that a slight change in the chemical structure of MXene can also change other properties of the electron transport layer. This will reduce the barriers to the movement of electrons and improve the efficiency of solar cells. We were right.
The study, Functionalized-MXene-nanosheet-doped tin oxide improves the electrical properties of perovskite solar cells, is published in the open access journal Cell Reports Physical Science and can be read here.
