DFT study on some polythiophenes containing benzo[d]thiazole and benzo[d]oxazole: structure and band gap

The content of this paper focuses/shed light on the effects of X (X = S in P1 and X = O in P2) in C₁₁H₇NSX and R (R = H in P3, R = OCH₃ in P4, and R = Cl in P5) in C₁₈H₉ON₂S₂-R on structural features and band gaps of the polythiophenes containing benzo[d]thiazole and benzo[d]oxazole by the Density Function Theory (DFT) method/calculation. The structural features including the electronic structure lattice constant (a), shape, total energy (E_tot) per cell, and link length (r), are measured via band gap (E_g) prediction with the package of country density (PDOS) and total country density (DOS) of material studio software. The results obtained showed that the link angle and the link length between atoms were not changed significantly while the E_tot was decreased from E_tot = - 1904 eV (in P1) to E_tot = - 2548 eV (in P2) when replacing O with S; and the E_tot of P3 was decreased from E_tot = - 3348 eV (in P3) when replacing OCH₃, Cl on H of P3 corresponding to E_tot = - 3575 eV (P4), - 4264 eV (P5). Similarly, when replacing O in P1 with - S to form P2, the E_g of P1 was dropped from E_g = 0.621 eV to E_g = 0.239 eV for P2. The E_g of P3, P4, and P5 is E_g = 0.006 eV, 0.064 eV, and 0.0645 eV, respectively. When a benzo[d]thiazole was added in P1 (changing into P3), the E_g was extremely strongly decreased, nearly 100 times (from E_g = 0.621 eV to E_g = 0.006 eV). The obtained results serve as a basis for future experimental work and used to fabricate smart electronic device.