Electron-phonon coupling in crystalline organic semiconductors: Microscopic evidence for nonpolaronic charge carriers

Abstract

We consider electron(hole)-phonon coupling in crystalline organic semiconductors, using naphthalene for our case study. Employing a first-principles approach, we compute the changes in the self-consistent Kohn-Sham potential corresponding to different phonon modes and go on to obtain the carrier-phonon coupling matrix elements (vertex functions). We then evaluate perturbatively the quasiparticle spectral residues for electrons at the bottom of the lowest-unoccupied- (LUMO) and holes at the top of the highest-occupied (HOMO) band, respectively obtaining $Z_e\approx 0.74$ and $Z_h\approx 0.78$. Along with the widely accepted notion that the carrier-phonon coupling strengths in polyacenes decrease with increasing molecular size, our results provide a strong microscopic evidence for the previously conjectured nonpolaronic nature of band-like carriers in these systems.

final, published version

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• First principles calculations of anisotropic charge carrier mobilities in organic semiconductor crystals
• Quantum coherence and carriers mobility in organic semiconductors
• Quantum-entanglement aspects of polaron systems
• Polaronic signatures and spectral properties of graphene antidot lattices

Cited by in corpus (5)

• Electronic transport and quantum localization effects in organic semiconductors
• Band gap renormalization, carrier mobilities, and the electron-phonon self-energy in crystalline naphthalene
• Optical conductivity and optical effective mass in a high-mobility organic semiconductor: Implications for the nature of charge transport
• Quantum dynamics of the small-polaron formation in a superconducting analog simulator
• Effects of different electron-phonon couplings on spectral and transport properties of small molecule single-crystal organic semiconductors