South Korean scientists have developed ultra-thin solar cells that are flexible enough to wrap around regular pencils. This pliable solar cell powers the wearable electronics like fitness trackers and smart glasses. Recently, researchers reported this achievement in the Applied Physics Letters, a subsidiary of the American Physical Confederation. "Our solar cells are about 1 micron thick," said Jongho Lee, an engineer at Gwangju Science and Technology Institute. 1 micron thinner than an ordinary human hair. Compared with the latest results, standard solar cells are usually hundreds of times thicker. Even the most other ultra-thin solar cells are 2 to 4 times thicker than this. Researchers use gallium arsenide semiconductors to make such thin solar cells. Instead of using binders that increase material thickness, they print directly on a flexible substrate. Subsequently, the cell was cold-welded to the substrate electrode by pressurizing and melting at 170 ° C the outermost layer of a substance called a photoresist and acting as a temporary adhesive. After that, the photoresist is stripped off, leaving a direct bond between the metal and the metal. The metal substrate also serves as a reflector that reflects stray photons back into the solar cell. Researchers tested the cell's efficiency in converting sunlight into electrical energy and found it to be comparable to similar thicker solar cells. They also conducted bending tests and found that the batteries were bent around objects as small as 1.4 mm in radius. In the meantime, the team conducted a numerical analysis of the battery. Research shows that they experience a stress value of only 3.5 microns, a quarter of that of batteries. "Thinner batteries are stronger when bent, but they behave the same, even slightly better," Lee said. Systemic Fungicide,Aliette Fungicide,Systemic Fungicide For Plants,Endothermic Fungicide heydchem limited , https://www.heydchem.com
January 02, 2024