Journal article · Conference paper
Machine learning-based screening of complex molecules for polymer solar cells
Department of Applied Mathematics and Computer Science, Technical University of Denmark1
Cognitive Systems, Department of Applied Mathematics and Computer Science, Technical University of Denmark2
Department of Energy Conversion and Storage, Technical University of Denmark3
Atomic Scale Materials Modelling, Department of Energy Conversion and Storage, Technical University of Denmark4
Department of Physics, Technical University of Denmark5
Computational Atomic-scale Materials Design, Department of Physics, Technical University of Denmark6
Polymer solar cells admit numerous potential advantages including low energy payback time and scalable high-speed manufacturing, but the power conversion efficiency is currently lower than for their inorganic counterparts. In a Phenyl-C_61-Butyric-Acid-Methyl-Ester (PCBM)-based blended polymer solar cell, the optical gap of the polymer and the energetic alignment of the lowest unoccupied molecular orbital (LUMO) of the polymer and the PCBM are crucial for the device efficiency.
Searching for new and better materials for polymer solar cells is a computationally costly affair using density functional theory (DFT) calculations. In this work, we propose a screening procedure using a simple string representation for a promising class of donor-acceptor polymers in conjunction with a grammar variational autoencoder.
The model is trained on a dataset of 3989 monomers obtained from DFT calculations and is able to predict LUMO and the lowest optical transition energy for unseen molecules with mean absolute errors of 43 and 74 meV, respectively, without knowledge of the atomic positions. We demonstrate the merit of the model for generating new molecules with the desired LUMO and optical gap energies which increases the chance of finding suitable polymers by more than a factor of five in comparison to the randomised search used in gathering the training set.
Language: | English |
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Publisher: | AIP Publishing LLC |
Year: | 2018 |
Pages: | 241735 |
ISSN: | 10897690 and 00219606 |
Types: | Journal article and Conference paper |
DOI: | 10.1063/1.5023563 |
ORCIDs: | Mesta, Murat , Shil, Suranjan , García Lastra, Juan Maria , Jacobsen, Karsten Wedel , Thygesen, Kristian Sommer , Schmidt, Mikkel N. and 0000-0003-4404-7276 |