The power conversion
efficiency (η) is the most important
key to determine the efficiency of dye-sensitized solar cell (DSSC)
devices. However, the calculation of η theoretically is a challenging
issue since it depends on a large number of experimental and theoretical
parameters with extensive related data. In this work, η was
successfully predicted using the improved normal model with density
functional theory (DFT) and time-dependent density functional theory
(TD-DFT) for eight diphenylthienylamine-based (DP-based) dyes with
various π-bridge adsorbed on titanium dioxide. The titanium
dioxide is represented by a nanotube surface (TiO
2
NT);
this surface is rarely investigated in the literature. The π-linker
consists of five (DP1)- or six (DP2)-membered rings and contains none
to three nitrogen atoms (D0–D3). The reliability of the estimated
values was confirmed by the excellent agreement with those available
for the two experimentally tested ones (DP2-D0 and DP2-D2). The deviations
between the experimental and estimated values were in the ranges of
0.03 to 0.06 mA cm
–2
, 0.05 to 0.3 mV, and 0.37 to
0.18% for short-circuits current density (
J
sc
), open-circuit voltage (
V
oc
), power
conversion efficiency (%η), respectively. More importantly,
the results revealed that using pyridine (DP2-D1), pyrimidine (DP2-D2),
and 1,2,4-triazine (DP2-D3) improves the power conversion efficiencies
in the range of 6.03 to 6.90%. However, the cyclopenta-1,3-diene (DP1-D0)
shows superior performance with a predicted η value that reaches
9.55%.