Abstract
Hole and electron
transport in a fluorene based poly[(9,9 di n octylfluorenyl 2,7 diyl) alt --(benzo[2,1,3]thiadiazol 4,8 diyl)]
(F8BT) are investigated. It is shown that the current density versus voltage characteristics of F8BT hole and electron only
devices can be well de scribed using our recently introduced improved mobility model. For the material studied, we find the
width of the Gaussian density of states 0.11 eV for F8BT hole only devices, and 0.19 eV for F8BT electron only devices.
Apparently, the electron transport exhibits a significantly stronger energy disorder than hole transport. Furthermore, we
investigate the current density versus voltage characteristics of F8BT electron only devices doped with 4% and 10%
concentrations of n type dopant decamethylcobaltocene (DMC). It is demonstrated that our improved model can also be
applied to n type doping conjugated polymers and t he electron transport in doped conjugated polymers can be calculated
without needing to add an additional free electron background density . The width of the Gaussian density of states obtained
for doped electron only devices exhibits the same disorder as undoped hole only devices and a smaller disorder than
undoped electron only devices, indicating that the electron mobility can be enhanced by dop ing up to the hole mobility..
Keywords
Hole Transport Electron Transport F luorene based copolymer.
Citation
B. B. CUI, L. G. WANG, M. L. LIU, Y. GUO, W. ZHANG, Hole and electron transport in a fluorene based copolymer, Optoelectronics and Advanced Materials - Rapid Communications, 12, 9-10, September-October 2018, pp.512-516 (2018).
Submitted at: April 2, 2018
Accepted at: Oct. 10, 2018