The solar cell industry is the focus of competition in the international high-tech industry. Compared with traditional silicon solar cells, flexible lightweight thin film perovskite solar cells are based on thin film solar cells that can be bent, folded and low in weight. Because of their high efficiency, low cost, and simple preparation process, they become solar cell industry. One of the most disruptive competitors.

Although perovskite solar energy has the advantages of low cost and high conversion efficiency, the technology also has the disadvantages of water degradation and poor durability. In addition, the battery contains toxic substances, lead and lead dissolved in water will be discharged into the environment. There are advantages and disadvantages.

Now, many scientists want to create lead-free perovskite technology that does not affect conversion efficiency, such as trying to replace lead with tin, antimony, bismuth, antimony, copper and manganese. Some research teams have pointed out that tin has the greatest potential for application. Its external electronic shell structure is similar to that of lead, and its ionic radius is relatively small, which makes the material do not affect the lattice structure when bonding. Currently, the team has also tested various tins. The perovskite arrangement, such as the combination of tin and bismuth, creates a new perovskite layer.

Flexible perovskite solar cells can meet the special needs of aerospace space equipment, field military information equipment, solar powered drones, high-altitude detection equipment and a wide variety of consumer electronics such as mobile phones. The research team hopes to mass production as soon as possible and contribute to the development of civil emergency, military and green urban landscape lighting.

Recently, the Institute of Nano-regulation and Biomechanics of the Institute of Advanced Technology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences has made new progress in the development of flexible perovskite solar cells. The related research results are titled "Highly Flexible, Stable and Efficient Flexible Perovskite Solar Cells by Van der Waals Epitaxial Technology on Mica Substrate" and published online in "Nano Energy".

In 2019, a major breakthrough was made in the development of flexible electronic technology, and technological development of flexible perovskite solar cells has also made some progress. At the press conference of the first scientific and technological achievements of Xi'an Jiaotong University this year, there has been a precedent of 22% of the efficiency of flexible perovskite solar cells developed by Professor Wu Chaoxin and his team of Xi'an Jiaotong University .

At present, flexible wearable electronics has become the development trend of electronic components. Flexible batteries are the focus of their research and development and technical difficulties. The power supply has great limitations on the outdoor use, large-area fit and safety of wearable electronics. As the demand for wearable electronic products continues to increase, flexible solar cells are receiving more and more attention. At present, the substrate used for the preparation of flexible devices is mainly a polymer substrate. When the critical bending radius is reached, the transparent conductive layer is broken, resulting in severe attenuation of photoelectric properties, and water molecules easily pass through the polymer substrate, affecting The mechanical and long-term stability of the battery.

To solve the above problems, the Nano-Control and Biomechanics Research Laboratory and the joint research team of Shijiazhuang Railway University and Taiwan Jiaotong University have developed highly flexible, stable and efficient perovskite solar cells (PSC) on transparent mica substrates. The best photoelectric conversion efficiency (PCE) is 18.0%; the bending radius is as small as 5 mm, and the original efficiency is maintained at 91.7% after 5000 bending cycles. Its excellent performance is mainly due to the fact that the van der Waals force between the mica layers reduces the mechanical constraint of the substrate to the PSC device, resulting in higher mechanical bending properties.

Figure (a) is a photo of the flexible battery; Figure (b) is a TEM photograph of the device section; Figure (c) is the battery performance JV curve; Figure (d) is the device bending durability test result; Figure (e) is the device fatigue test result ; FIG. (f) is heat test results (85 ° C, 85% RH ).