Transportna svojstva pentacena, heksacena i njihovih BN analoga

Abstract

Istraživali smo transportna svojstva predstavnika acena, pentacena i heksacena i upoređivali ih sa transportnim svojstvima njihovih BN analognih struktura. Prelaz naelektrisanja sa jedne na drugu strukturu istražen je preko proračuna energija reorganizacije na osnovu DFT i Markusovog poluempirijskog pristupa, dok su se istraživanja transporta naelektrisanja duž struktura zasnivala na DFT proračunima i metodu neravnotežnih Grinovih funkcija (NEGF). Pažnja je bila posvećena i energetskom razmaku između najnižeg pobuđenog singletnog (S1) i tripletnog (T3) stanja, što je veličina važna za oblast termalno aktivirane odložene fluorescencije (TADF). Dobijeni rezultati indiciraju da obje grupe istraženih struktura imaju određene prednosti i mane. Prema energijama reorganizacije i I-V karakteristikama, pentacen i heksacen imaju bolja svojstva, dok sa aspekta TADF-a, bolja svojstva imaju BN analozi.

We have investigated transport properties of higher acenes pentacene and hexacene and compared it with the transport properties of their BN analogues. Charge hopping from one structure to another was investigated through calculations of reorganization energies based on DFT and Marcus semi empiric approach, while the investigation of charge transport along the investigated structures was based on DFT calculations and non-equilibrium Green's function (NEGF) method. Attention was also paid to the energy separation between the lowest excited singlet (S1) and triplet (T1) state, which is quantity that is important for the field of thermally activated delayed fluorescence (TADF). The obtained results indicate that both groups of investigated structures have certain advantages and drawbacks. According to the reorganization energies and I-V characteristics, pentacene and hexacene have better properties, while from the aspect of TADF, BN analogues of pentacene and hexacene have better properties.