Optical and transport properties of single crystal rubrene: A theoretical study

Optical and charge transport properties of single crystal rubrene are investigated using the multi-mode Brownian oscillator (MBO) model, the charge hopping model with quantum nuclear tunneling, and the Munn-Silbey approach. The MBO model is adopted to calculate absorption and photoluminescence spectra, yielding results in excellent agreement with measurements. In addition, temperature dependence of zero phonon lines (ZPL) and phonon sidebands (PSBs) of absorption spectra is also examined using the MBO model, revealing a nearly linear dependence of line widths of the ZPL and the PSBs on temperature. Model parameters obtained from MBO fitting and TD-DFT computation are then utilized for hole mobility calculations. It is found that temperature dependence of the calculated mobility is in general agreement with measurements, exhibiting “band-like” transport behavior.