Study of the Hole and Electron Transport in Amorphous 9,10-Di-(2′-naphthyl)anthracene: The First-Principles Approach

Abstract

An accurate description of charge transport in amorphous organic semiconductors is challenging. Many previously reported methods largely involve empirical parameters, which may hinder the understanding of the charge transport process in a specific material. In this paper, Born–Oppenheimer molecular dynamics (BOMD) is used to simulate the amorphous structure of a widely used small molecule 9,10-di-(2′-naphthyl)anthracene (ADN). Its hole and electron mobilities are calculated using an ab initio method. It is found that the inaccuracy in the calculation of the nonadiabatic couplings caused by the periodicity of the cell in the BOMD simulation can be greatly reduced by taking into account the mirror states in the surrounding cells. The calculated hole and electron mobilities both have the same order of magnitude with their corresponding experimental results, demonstrating the possibility to obtain reasonable charge transport mobilities for amorphous small-molecule semiconductors via the first-principles approach. Our work may shed light on the understanding of the charge transport process in amorphous organic semiconductors and the design of new charge transport materials.

From charge transport parameters to charge mobility in organic semiconductors through multiscale simulation

“…[13][14][15][16][17][18] (iii) V is much less than l, and the electron interacts strongly with intramolecular vibrations which eventually lead to self-localization: hopping model applies in this case. Although the localized charge model proposed by Bre ´das et al 19 has achieved great successes in molecular design to achieve high charge mobility, [20][21][22][23][24][25][26] there are still some issues unsolved, 26 such as the involvement of molecular excited states of the ions in evaluating the electronic coupling term, the treatment of site variability, especially for amorphous organic films, 28 and the involvement of the nuclear tunneling effect in the charge transfer process. 29 Marcus semi-classical theory 30 relied on classical treatment of nuclear motions in organic semiconductors.…”

Pure aromatic hydrocarbons with rigid and bulky substituents as bipolar hosts for blue phosphorescent OLEDs

“…13 Due to their strong fluorescence, they have been adopted in the field of OLEDs as dopant emitters 1,[14][15][16] and proved to be able to improve device stability. 14 Further studies demonstrated that pure aromatic hydrocarbons of anthracene derivatives exhibit both electron and hole transporting properties, [17][18][19] and can be used as host emitters in OLEDs. 20,21 Due to their good conjugation and the lack of preferential moieties either for hole or for electron transport, pure aromatic hydrocarbons are expected to possess high and bipolar carrier transport properties, which are highly desired for host components in OLEDs, such as hosts for phosphors in phosphorescent OLEDs (PhOLEDs).…”

Multiscale simulation of charge transport in a host material, N,N′-dicarbazole-3,5-benzene (mCP), for organic light-emitting diodes

“…One of the reasons is that large-scale, high computational cost MD simulations are required to reproduce actual amorphous systems. Also, the method has only been applied to Alq 3 , [31][32][33][34][35][36] and 2,8-bis(triphenylsilyl)-dibenzofuran (BTDF), 37 9,10-di-(2 0 -naphthyl)anthracene (ADN), 38 and N,N 0bis(1-naphthyl)-N,N 0 -diphenyl-1,1 0 -biphenyl-4,4 0 -diamine (NPD) 39 so far. The theory should be applied to other important molecular systems for understanding charge transfer phenomena in organic amorphous systems and for the development of excellent charge transfer materials.…”