Rapid progress in organic electronics demands new highly efficient organic semiconducting materials. Nevertheless, only few materials have been created so far that show reliable band-like transport with high charge mobilities, which reflects the two main obstacles in 2 the field: the poor understanding of charge transport in organic semiconductors (OSs) and the difficulty of its quantification in devices. Here, we present a spectroscopic method for assessment of the charge transport in organic semiconductors. We show that the intensities of the lowfrequency Raman spectrum allow calculation of the dynamic disorder that limits the charge carrier mobility. The spectroscopically evaluated mobility clearly correlates with the device charge mobility reported for various OSs. The proposed spectroscopic method can serve as a powerful tool for a focused search of new materials and highlights the disorder bottleneck in the intrinsic charge transport in high-mobility organic semiconductors. (phonons) tend to localize the charge carrier at one molecule. This prevents coherent charge transport and results in charge hopping with low µ, which is observed in most of OSs. 4,5 Interaction of charge carriers with vibrationselectron-phonon couplinginvolves local (Holstein) and non-local (Peierls) contributions. The local one stems from modulation of molecular energy levels, mainly by intramolecular vibrations in the high-frequency (HF) spectral range, and is quantified by the reorganization energy, λ. 4 The non-local contribution results from modulation of J mainly by low-frequency (LF) vibrations (inter-, intramolecular, or mixed 6,7 ), and is characterized by the lattice distortion energy, L. 1 The frontier of LF range is usually set at ω = 200 cm -1 , which corresponds to the energy of room-temperature thermal vibrations.According to the recent theoretical studies, 8-11 the coupling of charge carriers to LF vibrations sets the limit for coherent charge transport in high-µ OSs. These vibrations are thermally populated at ambient conditions and hence have large atomic displacements with the result of strong dynamic disordervariance of charge transfer integrals, 2 2 J J = . 4,12 Dynamic disorder decreases the delocalization length of charge carrier, LD, and hence decreases µ. 8-10 While multiple theoretical studies have addressed the impact of dynamic disorder on charge transport, 1,8-14 the experimental data that could verify the models and provide a criterion for screening promising OSs with weak electron-phonon interaction are extremely scarce. [15][16][17][18][19] Specifically, although the experimental LF vibrational spectra were used for verification of simulations, 19 direct probing of the dynamic disorder was not performed so far.Raman spectroscopya standard tool for vibrational spectrum characterization of OSs 20-24gives the most direct access to electron-phonon coupling. The Raman signal is determined by the vibrational modulation of the electronic properties, namely, the material polarizability. 20,25 The latter strong...