Charge-transfer transitions in crystalline anthracene and their role in photoconductivity

摘要: Abstract Electric-field modulated absorption spectra of polycrystalline anthracene layers delineate existence a series five charge-transfer bands that can be assigned to transitions within the ab crystal plane. The energy versus distance relationship is coulombic (e = 3.2) yielding an optical band gap Egopt 4.4±0.05 eV. Absorption coefficients are about one order magnitude lower than calculated by Bounds et al. and indicate coupling constant A ∼ 0.15 for interaction between CT Frenkel exciton states. Previous data intrinsic free-carrier production, in particular dependence “thermalization” distance, consistently interpreted terms dissociation pairs if assumption made vibrational (0.3 eV) fully or part used additional separation electron-hole pair. adiabatic (electrical) Ege1 4.1±1