Azeem Urwah, Khera Rasheed Ahmad, Naveed Ayesha, Imran Muhammad, Assiri Mohammed A, Khalid Muhammad, Iqbal Javed
Department of Chemistry, University of Agriculture, Faisalabad 38000, Pakistan.
Department of Chemistry, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.
ACS Omega. 2021 Oct 20;6(43):28923-28935. doi: 10.1021/acsomega.1c03975. eCollection 2021 Nov 2.
With the aim of upgrading the power conversion efficiency of organic solar cells (OSCs), four novel non-fullerene, A-A-D-A-A-type small molecules were designed that are derivatives of a recently synthesized molecule reported for its efficient properties in all-small-molecule OSCs (ASM-OSCs). Optoelectronic properties of the designed molecules were theoretically computed with a selected CAM-B3LYP functional accompanied by the 6-31G(d,p) basis set of density functional theory (DFT), and excited-state calculations were performed through the time-dependent self-consistent field. The parameters of all analyzed molecules describing the charge distribution (frontier molecular orbitals, density of states, molecular electrostatic potential), absorption properties (UV-vis absorption spectra), exciton dynamics (transition density matrix), electron-hole mobilities (reorganization energies), and exciton binding energies were computed and compared. All the designed molecules were found to be superior regarding the aforesaid properties to the reference molecule. Among all molecules, has the smallest band gap (3.88 eV) and the highest absorption maxima with broad absorption in the visible region. has the lowest binding energy (1.51 eV in chloroform solvent) ensuring easier and faster dissociation of excitons to produce free charge-carriers and has the highest open-circuit voltage (2.46 eV) with PCBM as the acceptor. possesses the highest hole mobility because it has the lowest value of λ (0.0148 eV), and exhibits the highest electron mobility because it has the lowest value of λ (0.0146 eV). All the designed molecules are good candidates for ASM-OSCs owing to their superior and optimized properties.
为了提高有机太阳能电池（OSC）的功率转换效率，设计了四种新型非富勒烯A-A-D-A-A型小分子，它们是最近合成的一种分子的衍生物，该分子在全小分子有机太阳能电池（ASM-OSC）中具有高效性能。使用选定的CAM-B3LYP泛函并结合密度泛函理论（DFT）的6-31G(d,p)基组对设计分子的光电性质进行了理论计算，并通过含时自洽场进行了激发态计算。计算并比较了所有分析分子描述电荷分布（前沿分子轨道、态密度、分子静电势）、吸收性质（紫外可见吸收光谱）、激子动力学（跃迁密度矩阵）、电子-空穴迁移率（重组能）和激子结合能的参数。发现所有设计分子在上述性质方面均优于参考分子。在所有分子中，[具体分子名称1]具有最小的带隙（3.88 eV）和最高的吸收最大值，在可见光区域有宽吸收。[具体分子名称2]具有最低的结合能（在氯仿溶剂中为1.51 eV），确保激子更容易、更快地解离以产生自由电荷载流子，并且以PCBM作为受体时具有最高的开路电压（2.46 eV）。[具体分子名称3]具有最高的空穴迁移率，因为它具有最低的λ值（0.0148 eV），而[具体分子名称4]表现出最高的电子迁移率，因为它具有最低的λ值（0.0146 eV）。由于其优异和优化的性质，所有设计分子都是ASM-OSC的良好候选材料。
