Phys.org  April 14, 2023 In a usual solar cell, the energy of a single photon is transferred to two free charges in the material. However, a few molecular materials like pentacene are an exception and show conversion of one photon into four charges, instead. This excitation doubling, which is called exciton fission, could be extremely useful for high-efficiency photovoltaics, specifically to upgrade the dominant silicon-based technologies. An international team of researchers (Germany, Canada) used time- and angle-resolved photoemission spectroscopy to observe the primary step of singlet fission in crystalline pentacene. Their results indicated a charge-transfer mediated mechanism with a hybridization […]