12-15 July 2011
Saint George Hotel
Africa/Johannesburg timezone

Non-linear Fowler-Nordheim plots in thin film polymer-fullerene composite devices: Transition from electron-only to hole-only conduction

14 Jul 2011, 11:15


Oral Presentation Track A - Condensed Matter Physics and Material Science CMPMS2


Dr Zivayi Chiguvare (University of the Witwatersrand)


We studied charge injection and transport mechanisms in blends of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methylester (PCBM), by analysing dark, temperature dependent current-voltage characteristics of the P3HT:PCBM blend thin films sandwiched between aluminium electrodes in a MIM configuration. We present a general method of interpreting Fowler - Nordheim plots of metal/semiconductor/metal devices with pronounced non-linear characteristics by dividing them into several regions based on physical origins. We show that by applying appropriate electric fields it is possible to switch from electron-only conduction to hole-only conduction in a single Al/P3HT:PCBM/Al device. We affirm that electrons can be selectively transported through the lowest unoccupied molecular orbital of PCBM at low applied voltages and low temperatures; and alternatively holes can be transported through the highest occupied molecular orbital of P3HT at higher applied voltages and high temperature, within a single device.

Level (Hons, MSc, <br> &nbsp; PhD, other)? PhD
Consider for a student <br> &nbsp; award (Yes / No)? No
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)? Yes

Primary author

Dr Zivayi Chiguvare (University of the Witwatersrand)

Presentation Materials