Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur Campus, Mohanpur-741252, Nadia, West Bengal, India.
J Chem Phys. 2014 Mar 28;140(12):124317. doi: 10.1063/1.4869582.
We studied the nature of the ground state and low-lying excited states of armchair polyacene oligomers (Polyphenanthrene) within long-range Pariser-Parr-Pople model Hamiltonian with up to 14 monomers using symmetrized density matrix renormalization group technique. The ground state of all armchair polyacenes studied is found to be singlet. The results show that lowest singlet dipole allowed excited state has higher energy for armchair polyacenes as compared to linear fused polyacenes. Moreover, unlike linear fused polyacenes, the lowest singlet excited state of these oligomers is always found to lie below the lowest dipole forbidden two-photon state indicating that these armchair polyacene oligomers strongly fluoresce. The calculations of low-lying excitations on singly and triply electron doped armchair polyacene oligomers show a low energy band with strong transition dipole moment that coupled to charge conductivity. This implies armchair polyacene posses novel field-effect transistor properties.
我们使用长达 14 个单体的对称化密度矩阵重整化群技术，在长程 Pariser-Parr-Pople 哈密顿模型下研究了扶手椅型多并苯低聚物（芘）的基态和低激发态的性质。我们发现所有研究的扶手椅型多并苯的基态都是单重态。结果表明，与线性稠合多并苯相比，扶手椅型多并苯的最低单重态偶极允许激发态具有更高的能量。此外，与线性稠合多并苯不同的是，这些低聚物的最低单重激发态总是低于最低的双光子禁阻态，这表明这些扶手椅型多并苯低聚物具有强烈的荧光性质。对单电子和三电子掺杂的扶手椅型多并苯低聚物的低激发态的计算表明，存在一个具有强跃迁偶极矩的低能能带，与电荷传导耦合。这意味着扶手椅型多并苯具有新型的场效应晶体管性质。
