Excimer-laser micropatterned photobleaching as a means of isolating polymer electronic devices

Itoh, Eiji; Torres, I.; Hayden, Christopher J.; Taylor, David

doi:10.1016/j.synthmet.2005.10.015

Cited by 12 publications

(14 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…7 Figure 1 shows the C-V plots obtained at 130 Hz for a range of temperatures while cycling the gate voltage from −30 to + 30 V and back to −30 V at a rate of 0.5 V / s. At the highest negative voltages the devices are in accumulation, yielding the insulator capacitance C I ϳ 800 pF ͑84.2 nF/ cm 2 ͒ for the ATO, corresponding to a dielectric constant ϳ 21 intermediate between those of Al 2 O 3 ͑ = 8.4͒ and TiO 2 ͑ =41͒. When measured using gold electrodes only, the dielectric constant of the ATO film was estimated to be ϳ16 and close to the value ͑ϳ14͒ reported by Fortunato et al 8 The higher value obtained from the MIS structure here is due to significant lateral conduction through the P3HT layer 9 at the low measurement frequency used here, which effectively increases the device area in the absence of a guard ring.…”

supporting

confidence: 79%

Voltage- and light-induced hysteresis effects at the high-k dielectric—poly(3-hexylthiophene) interface

Lancaster

Taylor

Sayers

et al. 2007

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

supporting

confidence: 79%

Voltage- and light-induced hysteresis effects at the high-k dielectric—poly(3-hexylthiophene) interface

Lancaster

Taylor

Sayers

et al. 2007

Applied Physics Letters

View full text Add to dashboard Cite

show abstract

“…In the absence of the guard ring, lateral currents flow along the semiconductor in an attempt to charge the whole of the gate capacitance. The effect becomes especially marked at the low frequencies 5 necessary for investigating interface state effects and can only be limited using a guard ring.…”

Section: Fig 1 ͑A͒mentioning

confidence: 99%

“…Although necessary for limiting lateral conduction along the semiconductor, 5 the guard ring in combination with the top and bottom electrodes act as a parasitic MISFET with zero source-drain bias. Consequently, it also will have a small-signal response that contributes to the total device admittance.…”

Section: Theoretical Modelmentioning

confidence: 99%

Separating interface state response from parasitic effects in conductance measurements on organic metal-insulator-semiconductor capacitors

Taylor

Alves

2008

Journal of Applied Physics

View full text Add to dashboard Cite

A simple model is developed for the admittance of a metal-insulator-semiconductor ͑MIS͒ capacitor which includes the effect of a guard ring surrounding the Ohmic contact to the semiconductor. The model predicts most of the features observed in a MIS capacitor fabricated using regioregular poly͑3-hexylthiophene͒ as the active semiconductor and polysilsesquioxane as the gate insulator. In particular, it shows that when the capacitor is driven into accumulation, the parasitic transistor formed by the guard ring and Ohmic contact can give rise to an additional feature in the admittance-voltage plot that could be mistaken for interface states. When this artifact and underlying losses in the bulk semiconductor are accounted for, the remaining experimental feature, a peak in the loss-voltage plot when the capacitor is in depletion, is identified as an interface ͑or near interface͒ state of density of ϳ4 ϫ 10 10 cm −2 eV −1 . Application of the model shows that exposure of a vacuum-annealed device to laboratory air produces a rapid change in the doping density in the channel region of the parasitic transistor but only slow changes in the bulk semiconductor covered by the gold Ohmic contact.

show abstract

“…Prior to making measurements, the excess P3HT film around the top electrodes was carefully removed by mechanical scribing to minimise possible lateral current effects [22,23]. Then, to remove solvent traces and any adventitious P3HT dopants (e.g.…”

Section: Mis Capacitor Fabricationmentioning

confidence: 99%

Interface state contribution to the photovoltaic effect in organic phototransistors: Photocapacitance measurements and optical sensing

Watson

Lopes

Oliveira

et al. 2018

Organic Electronics

Self Cite

View full text Add to dashboard Cite

We report the results of an investigation into the contribution that trapping in interface states makes to the photovoltaic effect observed in organic phototransistors. To isolate this effect from other processes that occur in the transistor structure when under illumination, we focus attention on the photo-response of metal-insulatorsemiconductor (MIS) capacitors-the core structure of transistors. The capacitors comprised poly(3-hexylthiophene), (P3HT), as the active semiconductor in combination with one of three insulators, namely, poly (amide-imide), (PAI), SU-8 photoresist and polysilsesquioxane (PSQ). Following initial characterization in the dark, the capacitor response was measured both during and after irradiation with light in the wavelength range 400-700 nm. Three different approaches were employed to study the photo-response, each providing a different insight into the processes occurring. Capacitance-voltage sweeps before, during and after illumination provided direct evidence supporting the view that the photovoltaic effect occurred as a result of electron trapping in interface states of density up to ∼2 × 10 12 cm −2 in the P3HT/PAI combination but lower for SU-8 and PSQ. The dynamic photo-response, in which device capacitance was held constant by changing the applied bias, showed a fast component related to optically induced photoconduction in the semiconductor and a slower component reflecting the dynamics of interface electron trapping. Finally, photo-induced capacitance changes occurring with constant applied voltage were used to demonstrate a simple 3 × 3 imaging array.

show abstract

Excimer-laser micropatterned photobleaching as a means of isolating polymer electronic devices

Cited by 12 publications

References 29 publications

Voltage- and light-induced hysteresis effects at the high-k dielectric—poly(3-hexylthiophene) interface

Voltage- and light-induced hysteresis effects at the high-k dielectric—poly(3-hexylthiophene) interface

Separating interface state response from parasitic effects in conductance measurements on organic metal-insulator-semiconductor capacitors

Interface state contribution to the photovoltaic effect in organic phototransistors: Photocapacitance measurements and optical sensing

Contact Info

Product

Resources

About