Moradpour Batool, Omidyan Reza
Department of Chemistry, University of Isfahan 81746-73441 Isfahan Iran
RSC Adv. 2024 Jun 25;14(28):20278-20289. doi: 10.1039/d4ra03334e. eCollection 2024 Jun 18.
In this study, we investigate photophysical properties of eight inorganic Pt(ii) complexes containing the bzq (benzoquinoline) ligand for OLED applications using high-level density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. We explore the radiative and non-radiative relaxation constants ( , ), spin-orbit coupling (SOC) matrix elements, and spectral properties. To ensure compatibility between the host and guest compounds, we determine the HOMO and LUMO energy levels, as well as the triplet excitation energies of the selected systems, and evaluate their efficiency for OLED devices. Our findings indicate that all systems, except for 2a and 2b, exhibit a small S-T energetic gap (Δ ≤ 0.60 eV) and promising SOC matrix elements (25-93 cm), leading to a significant intersystem crossing (ISC) process. These complexes also show promising radiative relaxation rates ( = ∼10 s) and high phosphorescent quantum yields ( > 30%). Thus, our results confirm that six out of the eight selected Pt(ii) complexes are promising candidates for use in the emitting layer (EML) of OLED devices as efficient green emitters.
在本研究中，我们使用高水平密度泛函理论（DFT）和含时密度泛函理论（TD-DFT）计算，研究了八种含有苯并喹啉（bzq）配体的无机铂（II）配合物用于有机发光二极管（OLED）应用的光物理性质。我们探究了辐射和非辐射弛豫常数（ ， ）、自旋轨道耦合（SOC）矩阵元以及光谱性质。为确保主体和客体化合物之间的兼容性，我们确定了所选体系的最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）能级以及三重态激发能，并评估了它们在OLED器件中的效率。我们的研究结果表明，除了2a和2b之外，所有体系都表现出较小的单重态-三重态能量间隙（Δ ≤ 0.60 eV）和有前景的SOC矩阵元（25 - 93 cm），导致显著的系间窜越（ISC）过程。这些配合物还显示出有前景的辐射弛豫速率（ = ∼10 s）和高磷光量子产率（ > 30%）。因此，我们的结果证实，所选的八种铂（II）配合物中有六种有望作为高效绿色发光体用于OLED器件的发光层（EML）。
