Can True Space-Charge-Limited Currents be Observed in (pi-symbol)-Conjugated Polymers

Journal Article · Sun Jan 01 04:00:00 EST 2006 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2201859· OSTI ID:976973

Gregg, B A; Gledhill, S E; Scott, B

The observation of space-charge-limited (SCL) currents in hole conductors requires that the hole density injected at the electrode, p{sub inj}, overwhelm the bulk free hole density p{sub f}. It also requires that any mobile ion density n{sub ion} be insignificant. SCL currents are often claimed in amorphous films of {pi}-conjugated polymers. However, we estimate p{sub f} in poly(p-phenylene-vinylene) derivatives from the conductivities and carrier mobilities as 10{sup 17}-10{sup 19} cm{sup -3} and show that even if n{sub ion} = 0, the currents in {pi}-conjugated polymers are often better described as Poole-Frenkel (PF) currents. When n{sub ion} > 0, even the PF model is an oversimplification.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO.
• Sponsoring Organization: USDOE
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 976973
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11, 2006 Vol. 99; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

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