Seed project: Screening Polycyclic Aromatic Hydrocarbons for Singlet Fission Candidates
Abstract
Singlet fission (SF) is the down-conversion of one photogenerated singlet exciton into two triplet excitons. SF may significantly increase the efficiency of organic photovoltaics by harvesting two charge carriers from one photon. Few chromophores are presently known to exhibit intermolecular SF with high efficiency, hindering the realization of solid-state SF solar cells. The chemical compound space of possible chromophores is infinitely vast and largely unexplored. Exploring this configuration space by experimental means alone would be unfeasible. SF is a collective many-body quantum mechanical process, involving electrons and holes whose correlated wave-functions may extend over several molecules. The mechanism of SF and the factors governing its efficiency are only partially understood. The goal of the proposed research is to advance the fundamental understanding of SF and discover new SF chromophores. To this end, we propose to develop a new computational approach, combining many-body perturbation theory (MBPT) methods for electronic excitations with machine learning (ML) algorithms to enable high throughput prediction of SF chromophores. Within this seed project we will use MBPT to investigate the excitonic properties of a set of polycyclic aromatic hydrocarbons (PAHs) extracted from the Cambridge Structural Database (CSD), as most known SF chromophores belong to this chemical family. This will serve a dual purpose of discovering SF candidates within the PAH set and generating reference data for ML. At a later stage, ML algorithms for feature selection will be used to identify predictive descriptors that are fast to evaluate and correlate strongly with SF efficiency. This would eventually enable high throughput screening of larger data sets for SF chromophores.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 11, 2018
- Source ID
- FA95501810248
Entities
People
- Noa Marom
Organizations
- Air Force Office of Scientific Research
- Massachusetts Institute of Technology
- United States Air Force