Highly efficient wet-processed solar cells with molecules within the same orientation
Solar cells are an economical , alternate source of energy. A subtype of those , organic solar cells make use of organic polymers inside the cell. Using these polymers makes the cells light-weight and increases their flexibility. Organic solar cells are produced by two different chemical methods: dry processing and wet processing, with the latter being a faster method. There are several parameters wont to assess the efficiency of solar cells with absorption of sunshine and transportation of charge being widely used. A prevailing problem with the structure of organic cells is that molecules within the active organic layer liable for light absorption and charge transport tend to face both towards the sides of cells, also as towards the sunshine absorbing substrate. Maximizing the amount of molecules facing the substrate, however, is that the key to maximising absorption and conductivity of the cell. Scientists have modified the dry processing method to realize such an orientation, but it's not been possible with the wet method. The research team led by Tetsuya Taima at Kanazawa University, is that the first to successfully do so. The premise of their method is that the introduction of a copper iodide (CuI) layer between the active molecules and therefore the substrate. In their study, the researchers used a movie of active molecules called DRCN5T and coated them onto either CuI/PEDOT: PSS (30 nm)/indium tin oxide (ITO) mixed substrates, or substrates without the CuI layer. The ratio of substrate facing to edge facing DRCN5T molecules was then compared between both. Subsequent high-resolution imaging revealed that the CuI containing cells had active molecules with a ten times higher substrate facing orientation, along side enhanced light absorption. The researchers attributed this altered orientation of the molecules to strong chemical interactions between the DRCN5T and CuI atoms. To further confirm this, DRCN5T molecules with bulky side chains that don't interact with CuI were used, and a better substrate facing ratio wasn't seen. This is the primary study that effectively demonstrates a way of manufacturing such efficient organic solar cells using the wet processing method. Besides saving time, the wet method also leads to larger film areas. “This technique is predicted to greatly contribute to the event of organic thin film solar cells fabricated by wet processing within the future,” conclude the authors. Their approach paves the way for producing high-performance solar cells faster.
Source: https://timestech.in/highly-efficient-wet-processed-solar-cells-with-molecules-in-the-same-orientation/
