1. Exciton Fission in Solid Tetracene and Related Materials: a Possible Strategy for High Efficiency Organic Solar Cells
Increasing the yield of charge carriers per absorbed photon is one way to improve the photovoltaic efficiency of organic solar cells. The singlet and triplet energy levels of tetracene and its derivatives permit two triplet excitons to be generated by one singlet exciton. Exciton fission, where the intially excited singlet state spontaneously splits into a triplet pair state, provides the opportunity to extract two electron-hole pairs per absorbed photon without the requirement of quantum confinement. We are currently studying the basic photophysics of tetracene both in monomer and crystalline form. We have assigned the transient absorption spectrum of tetracene in solution as a preliminary step for understanding its spectroscopy in the crystal. In the solid state spectra, we have identified the superradiant exciton and the induced triplet absorption.
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DA/A
Wavelength (nm)
Monomer in toluene
Solid film
Exciton Fission