Abstract
In this paper, the charge carrier transport and energetic disorder in photovoltaic blends of regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene (PCBM) with different annealing temperatures have been studied. It is demonstrated that the current density versus voltage (J -V ) characteristics of both P3HT hole-only device and PCBM electron-only device can be accurately described by using our recently introduced improved mobility model. Furthermore, the J -V characteristics of P3HT:PCBM blends that were measured in hole-only and electron-only devices for different annealing temperatures can also be accurately described by the improved mobility model. Additionally, we find that the width of the Gaussian density of states σ and zero-field mobility of holes and electrons in P3HT:PCBM blends are the function of thermal annealing temperature. For both hole-only and electron-only devices based on P3HT:PCBM blends, the hole and electron mobilities gradually increase with increasing the annealing temperature, while the width of the Gaussian density of states σ gradually decreases with increasing the annealing temperature, indicating the mobility is closely related to the energetic
disorder. These results suggest that the amount of energetic disorder in disordered organic semiconductors appears to govern the charge transport.
Keywords
Charge transport, Energetic disorder, Disordered organic semiconductors.
Citation
B. B. CUI, L. G. WANG, L. ZHANG, Y. J. WANG, Charge carrier transport and energetic disorder in poly (3-hexylthiophene):methanofullerene photovoltaic blends, Optoelectronics and Advanced Materials - Rapid Communications, 14, 1-2, January-February 2020, pp.78-83 (2020).
Submitted at: Sept. 25, 2019
Accepted at: Feb. 17, 2020