Designing of DAD Type Small Semiconductor Molecules andInvestigation of Substituent Effect on Their Molecular, Electronic and Optical Properties: A DFT Study**


SEYİTDANLIOĞLU ŞİRİN P. , KAHYA N. D. , ÜNALEROĞLU C.

CHEMISTRYSELECT, vol.6, no.40, pp.10793-10801, 2021 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 6 Issue: 40
  • Publication Date: 2021
  • Doi Number: 10.1002/slct.202103353
  • Title of Journal : CHEMISTRYSELECT
  • Page Numbers: pp.10793-10801
  • Keywords: Computational chemistry, Density functional calculations, Donor-acceptor systems, Semiconductors, Substituent effects, BENZOTRIAZOLE-BASED ACCEPTOR, OPEN-CIRCUIT VOLTAGE, SOLAR-CELLS, ENERGY-LEVELS, P-TYPE, PHTHALIMIDE, DONORS, BIOSENSORS, NANOPARTICLES, DERIVATIVES

Abstract

The design of multi-purpose semiconductor materials has become a major challenge in organic electronics. In this work, we designed DAD type 30 small molecules with thiophene as donor and phthalimide/benzimidazole/benzotriazole as acceptor groups and investigated their structural, electronic and optical properties via computational methods. E-HOMO, E-LUMO of the designed molecules were calculated with DFT and TD-DFT methods at HSEH1PBE functional with the 6-31+G** basis set. HOMO-LUMO gaps of the designed molecules were ranged between 2.25-3.41 eV. When an amino group is used as a substituent, the lowest HOMO-LUMO gaps (2.25-2.95 eV) were obtained with increasing HOMO level. Reorganization energies were calculated for hole or electron transport properties of the representative molecules. Benzotriazole based DAD compound, which is N-Phenyl bearing p-formyl substituted, has the smallest hole reorganization energy as a promising p-type organic semiconductor. High open-circuit voltages were obtained for aldehyde, carboxylic acid and ester substituted structures. This study presents a valuable insight to the experimental studies in designing new photovoltaics and electrochemical biosensors.