DFT Based Modeling of Asymmetric Non-Fullerene Acceptors for High-Performance Organic Solar Cell

AbstractFive new asymmetric NFA-based polymer solar cells i.e., N1-N5 are designed by doing modification in terminal groups of the acceptor part of experimentally synthesized reference molecule with (4,4,9,9-tetramethyl-4,9 dihydroselenopheno [2’,3’:5,6]-s-indaceno [1,2-b] thiophene) core. Frontier molecular orbital analysis is used to study their photovoltaic and optoelectronic properties. It confirmed the electrons' transportation from the donor to the acceptor part. It stated that all molecules have a lower bandgap than R and N2 has the lowest bandgap of 2.01 eV. The molecular orbital potential analysis confirmed the electron-withdrawing properties of the terminal groups. Optical properties studies evaluated maximum absorption with transition energies. All newly designed molecules N1-N5 show higher λmax values than R i.e., in the range of 680-740 nm with N2 having the highest λmax of 735 nm and lowest transition energy of 1.69 eV. Dipole moment studies showed that N3 has a maximum dipole moment of 7-40 D with all others having comparable values. TDM plots confirmed the electron shifting from donor to acceptor region. Reorganization energy analysis showed that N1 and N3 have the lowest reorganization energy values thus giving the highest electron mobilities. Voc calculated results of all molecules N1-N5 have lower values than R when coupled with PTB7-Th donor polymer. Charge transport analysis of N2 and PTB7-Th coupled molecule confirmed the acceptor type nature of our designed molecules.

Revealing the Microstructure-Related Light-induced Degradation for All-Polymer Solar Cells Based on Regioisomerized End-Capping Groups Acceptors

Given the state-of-the-art impressive power conversion efficiency (PCE) of all-polymer solar cells (all-PSCs) surpassing 17%, it’s getting increasingly urgent to achieve highly stable devices under long-term operational conditions. Herein, the...

Understanding the Molecular Mechanisms of Differences in Efficiency and Stability of All-polymer Solar Cells

In spite of the great success of all-polymer solar cells (all-PSCs) in terms of device efficiency mainly owing to the vigorous development of polymer donors (PDs) and polymer acceptors (PAs),...