In this study, five dyes comprising different donor moieties were proposed with a new design approach. In the triphenylamine (TPA) moiety, the lone pair electron on N takes part in resonance with three phenyl rings. As a result, the donating ability of TPA decreases in TPA-based dyes and hence the intramolecular charge transfer (ICT). We have proposed cycloalkyl moieties in place of phenyl moieties to stop the participation in the resonance of the lone pair with the other two phenyl rings so that the available lone pair on N will be pumped towards acceptor to achieve an efficient ICT. All dyes were subjected to density functional theory (DFT) and time-dependent DFT to evaluate their ground and excited-state properties. The projected density of state and natural bond orbital analyses were carried out to confirm the ICT from the donor to the acceptor moiety and also to comprehend the donating ability of the newly proposed donor moieties. The reorganization energy of the dyes was calculated to find out the conformational changes that occurred during photoexcitation. The dyes were attached to (1 0 1) anatase surface of TiO₂ to understand the electron transfer from the excited-state of the dye to the conduction band of the TiO₂. The adsorption energy of the dyes onto the (1 0 1) anatase surface of the TiO₂ was also evaluated. The absence of defect states in the density of states spectrum indicated the smooth electron transfer at the dye/TiO₂ interfaces.

在这项研究中，用一种新的设计方法提出了五种包含不同供体部分的染料。在三苯胺（TPA）部分中，N上的孤对电子与三个苯环共振。结果，在基于TPA的染料中TPA的供体能力降低，因此分子内电荷转移（ICT）降低。我们已经提出了用环烷基部分代替苯基部分来阻止参与孤对与其他两个苯环的共振，从而使N上可用的孤对将被泵送到受体上，以实现有效的ICT。所有染料均接受密度泛函理论（DFT）和时间依赖性DFT评估其基态和激发态性质。进行了预计的状态和自然键轨道密度分析，以确认从供体到受体部分的ICT，并了解新提议的供体部分的供体能力。计算染料的重组能以找出光激发过程中发生的构象变化。将染料附着到TiO（1 0 1）锐钛矿表面参照图₂了解电子从染料的激发态到TiO ₂的导带的转移。还评估了染料在TiO ₂的（1 0 1）锐钛矿表面上的吸附能。在状态密度谱中没有缺陷状态表明在染料/ TiO ₂界面上电子的平稳转移。