Abstract
We report a study on the non-adiabatic molecular dynamics (NA-MD) of the charge transfer (CT) process in the boron subphtalocyanine chloride (SubPc)/fullerene (C60) interface using our newly implemented Libra-X software package, which is based on an interface of the Libra NA-MD library and the GAMESS electronic structure software. In particular, we address the following aspects of the simulation protocol: (a) the choice of the potential used to treat interatomic interactions and its effect on the structures of the complex and CT rates; (b) the choice of the electronic structure methodology used; and (c) the choice of the trajectory surface hopping (TSH) methodology used. From our analysis of the electronic structure, we suggest that the distortion of the SubPc conical structure affects orbital localization and that the "breathing" motion of SubPc drives the CT process in SubPc/C60. This study illustrates that the choice of the TSH methodology and electronic decoherence are crucial for the CT simulation. We extend our analysis of CT in SubPc/(C60)n models by increasing the number of C60 molecules up to n = 4. We find that the details of the interfacial SubPc/(C60)n geometry determine the CT rate. Finally, we find the computed CT timescale to be in the range of 2.2-5.0 ps, which is in agreement with the experimentally determined timescale in the order of magnitude of ∼10 ps. The developed open-source Libra-X package is freely available on the Internet at https://github.com/Quantum-Dynamics-Hub/Libra-X.
Highlights
To study how the choice of electronic structure methodology affects the properties of 1-electron orbitals and electronic dynamics, we have considered two semiempirical approaches: (a) the Recife model 1 (RM1)[87] and (b) extended Huckel theory (EHT).[55,56,57]
We have reported the development of the opensource Libra-X software for atomistic non-adiabatic molecular dynamics (NA-MD) simulations within the neglect of back-reaction approximation (NBRA) and beyond
Our code relies on the Libra library for NA dynamics and on external electronic structure packages, namely GAMESS, Quantum Espresso, or Gaussian[09]
Summary
Organic photovoltaic (OPV) materials are among the most studied systems owing to their potential for manufacturing efficient and inexpensive solar cells.[1,2,3,4,5,6,7,8,9,10,11,12,13,14] Phthalocyanines constitute a class of organic chromophores that bear a close resemblance to the naturally occurring porphyrin molecules, which are employed in nature itself as the key components of photosynthetic complexes in plants and photosynthetic bacteria.[15,16] Both porphyrins and phthalocyanines are remarkable for their high molar extinction coefficient,[17,18] which is a prerequisite for efficient solar energy harvesting. The aforementioned FMO-NA-MD work revealed a number of important effects, it is known that the results of NA-MD calculations may be sensitive to the details of the methodologies and interactions employed.[58,59,60,61] It is important to understand the possible dependencies of the results on the choice of methodologies used for treating nuclear dynamics, electronic structures, and CT dynamics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
