Tuning the optoelectronic properties of triphenylamine (TPA) based small molecules by modifying central core for photovoltaic applications

Saba Zahid; Alvina Rasool; Rao Aqil Shehzad; Ijaz Ahmad Bhatti; Javed Iqbal

doi:10.1007/s00894-021-04867-1

Tuning the optoelectronic properties of triphenylamine (TPA) based small molecules by modifying central core for photovoltaic applications

J Mol Model. 2021 Aug 7;27(9):237. doi: 10.1007/s00894-021-04867-1.

Authors

Saba Zahid¹, Alvina Rasool¹, Rao Aqil Shehzad¹, Ijaz Ahmad Bhatti¹, Javed Iqbal^{2

3}

Affiliations

¹ Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan.
² Department of Chemistry, University of Agriculture, Faisalabad, 38000, Pakistan. javedkhattak79@gmail.com.
³ Punjab Bio-Energy Institute, University of Agriculture, Faisalabad, 38000, Pakistan. javedkhattak79@gmail.com.

PMID: 34363112
DOI: 10.1007/s00894-021-04867-1

Abstract

Small donor molecules based on fused ring acceptors exhibit encouraging photovoltaic properties and expeditious advancement in organic solar cells. Central core modification of non-fullerene acceptor materials is a favorable methodology to enhance electronic properties and efficiency for OSCs. Herein, four new donor molecules, namely, BDTM1, PYRM2, ANTM3, and NM4 are designed with a strong donor moiety triphenylamine, tetracyanobutadiene as acceptor unit, and thiophene as spacer linked to a modified central core. Geometric parameters, optical, electrical properties, effect of central core modification on tailored molecules BDTM1-NM4 are investigated and compared with reference DPPR. DFT together with TDDFT approaches using MPW1PW91 functional is used to study key parameters like absorption maximum (λ_max), frontier molecular approach, ionization potential, electron affinity, the density of states, transition density matrix along with open-circuit voltage (V_OC), dipole moment and reorganization energy. Among all these molecules, BDTM1 shows maximum calculated absorption λ_max (817 nm) and the lowest band gap (2.54 eV). This bathochromic shift in BDTM1 is due to the presence of 4,8-dimethoxy-2,6-di-2-thienylbenzodithiophene as a strong electron-withdrawing group. Computed reorganization energies (RE) shows that BDTM1 has the highest hole and electron mobility among all designed molecules. Combination of BDTM1 donor and PC₆₁BM acceptor further verifies charge transfer and their interaction. The results illustrate that designed donor molecules (BDTM1-NM4) are better in performance and are recommended for experimentation to develop efficient OSCs. Four new donor molecules, namely, BDTM1, PYRM2, ANTM3, and NM4 are designed with a strong donor moiety triphenylamine, tetracyanobutadiene as acceptor unit and thiophene as spacer linked to a modified central core. Geometric parameters, optical, electrical properties, effect of central core modification on tailored molecules BDTM1-NM4 are investigated and compared with reference DPPR.

Keywords: Central core modification; Fused ring electron acceptors; Optical properties; Quantum simulation.