DFT Studies of p-N,N-(Dimethylamino) Benzoic Acid with Para or Meta–Electron Withdrawing or Donating Moieties for Dye-Sensitized Solar Cells (DSSCs)

Table 4

The calculated excitation energy (E), absorption wavelengths (λ_max), emission wavelength (λ_em), emission oscillator strength (f), light harvesting efficiency (LHE), excited-state lifetime (τ), and Stokes shift (SS) of dye D1 and its derivatives (D1.1-D1.7) in a DMSO solvent medium. They were calculated by using the TD-B3LYP/6-311++G level of theory.

Dyes	HOMO	LUMO	E∆	E (cm^−1)	λabs(nm)	λem(nm)	f	LHE	τ(ns)	Stokes shift (SS)
D1	−5.764	−1.423	4.341	31475	306	318	0.671	0.787	2.3	12
D1.1	−5.762	−1.669	4.093	31775	305	315	0.546	0.715	2.7	10
D1.2	−5.791	−1.655	4.136	31876	293	314	0.577	0.735	2.6	21
D1.3	−5.707	−1.749	3.958	32925	294	304	0.626	0.763	2.2	10
D1.4	−6.088	−1.541	4.547	32817	294	305	0.688	0.795	2.0	11
D1.5	−6.341	−2.425	3.916	28435	342	352	0.454	0.648	4.1	10
D1.6	−6.314	−3.300	3.014	30797	280	325	0.080	0.168	19.7	45
D1.7	−6.091	−2.383	3.708	25339	388	395	0.192	0.357	12.2	7