Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611, USA.
J Phys Chem A. 2012 Dec 13;116(49):12153-62. doi: 10.1021/jp3084315. Epub 2012 Nov 29.
A practical computational procedure has been proposed that provides key electronic parameters of a polymer (fundamental bandgap, ionization energy, electron affinity, and intrachain electron and hole mobilities) determining its suitability as a donor or acceptor in organic optoelectronic materials. Series of oligomer calculations at the Becke3-Lee-Yang-Parr level with and without a self-contained asymptotic correction using the 6-31G** basis set were performed. The bandgap, ionization energy, and electron affinities of a polymer are extrapolated from those of its oligomers obtained from the highest occupied and lowest unoccupied orbital energies in the Koopmans-like approximation. This scheme has been applied to conjugated polymers having the poly(p-phenylene), poly(thiophene), or poly(pyrrole) backbone as well as to PCBM. The observed values of the electronic parameters have been reproduced within less than 1 eV in most cases. With the predicted values of these parameters, estimates of the open-circuit voltage and drift potential have been made for 22 valid donor-acceptor combinations. Several potentially useful combinations have been identified including the poly(thiophene):PCBM. The electron and hole mobilities have been found to correlate more strongly with the conformation (planarity) than the bandgap, but otherwise do not differ significantly.
已经提出了一种实用的计算程序，该程序提供了聚合物的关键电子参数（基本带隙、电离能、电子亲和力以及链内电子和空穴迁移率），这些参数决定了其作为有机光电材料中的供体或受体的适用性。使用 Becke3-Lee-Yang-Parr 水平并带有或不带有自包含渐近校正的 6-31G**基组对一系列低聚物进行了计算。通过 Koopmans 类似近似从最高占据轨道和最低未占据轨道能量中获得聚合物的低聚物的带隙、电离能和电子亲和力被外推。该方案已应用于具有聚（对苯撑）、聚（噻吩）或聚（吡咯）主链的共轭聚合物以及 PCBM。在大多数情况下，电子参数的观测值在 1eV 以内得到了重现。利用这些参数的预测值，对 22 种有效的供体-受体组合进行了开路电压和漂移势的估算。已经确定了几种潜在有用的组合，包括聚（噻吩）：PCBM。发现电子和空穴迁移率与构象（平面性）的相关性比带隙更强，但除此之外没有显著差异。
