Abstract
In this paper, the hole transport and spatial correlations between the transport site energies in the TQ1:PC71BM
(poly[[2,3-bis(3-octyloxyphenyl)-5,8-quinoxalinediyl]-2,5-thiophenediyl]:[6,6]-phenyl C71 butyric acid methyl ester) blends as
used in organic photovoltaics are investigated. From an analysis of the temperature-dependent current density-voltage
(
J V
) characteristics of the TQ1:PC71BM hole-only device, it is found that consistent descriptions with equal quality can be
obtained using both the improved extended Gaussian disorder model (IEGDM) and the extended correlated disorder model
(ECDM). However, the intersite distance obtained using IEGDM is more realistic than the value obtained using ECDM, which
indicates that in the TQ1:PC71BM blends, the correlations between the transport site energies are absent. Based on a
comparison between analyses of the
J V
characteristics of the TQ1:PC71BM hole-only device using IEGDM and the
drift-diffusion simulations incorporating the extended correlated disorder model (DD+EGDM), it is demonstrated that the
diffusion has little effect on the charge transport in the TQ1:PC71BM blends. In addition, it is shown that the effective mobility
in the TQ1:PC71BM blends gradually increases with increasing temperature, and the maximum value of the carrier
concentration and the minimum value of the field strength appear at the interface of the TQ1:PC71BM hole-only device.
Keywords
Organic photovoltaics, Hole transport, Correlated disorder, Drift-diffusion.
Citation
L. H. LUO, L. G. WANG, Y. L. LIANG, L. ZHANG, Y. J. WANG, Effects of energetic disorder and diffusion on the hole transport in the TQ1:PC71BM photovoltaic blends, Optoelectronics and Advanced Materials - Rapid Communications, 16, 7-8, July-August 2022, pp.373-379 (2022).
Submitted at: March 31, 2022
Accepted at: Aug. 10, 2022