Coulomb Blockade Effect through Single Electron Tunneling Method in Cylindrical Gate Organic Light Emitting Transistor Configuration

In this paper, comparison among single gate organic light emitting transistor (SG-OLET), dual gate organic light emitting transistor (DG-OLET) and cylindrical organic light emitting transistor (C-OLET) are discussed in detail. Where the device structural and material parameter includes the pentacene(400 nm) as an organic semiconductor, PMMA/SiO2 (200 nm) is an insulator, the source and drain of Au (35 nm) along with Ni/Ti (5 nm) contact pads for tunneling electrons from source to drain and gate electrode of Si (200 nm). The extracted performance parameters for DG-OLET are drive current (Ids), threshold voltage (Vth), mobility (μ), and current on-off ratio (Ion/Ioff) are of 9.0 μA, 0.5 V, 1.1cm2/Vs and 2*108, respectively at Vgs of -3 V and Vds of 0 to -3 V. The observed results of DG-OLET are significantly higher in comparison to SG-OLET, whereas results of C-OLET is approximately comparable. Afterward, quantum dots (QDs) based single and dual OLETs are analyzed and observed the significantly higher drive current in both SG and DG-OLET devices in comparison to pentacene OSC based devices. Thereafter, coulomb blockade concept is discussed in-depth, because there is a need of coupling to their surroundings of electrodes by these structures which can either add or subtract electrons from the electrodes. Subsequently, single electron tunnelling (SET) phenomena is explained thoroughly. This method permits the optical and electrical behavior of the single-island structures of the SET. Light production is controlled by the gate voltage that controls the hole current. The results also indicate that OLET with high brightness can be fabricated by use of a light emitting conducting polymer. Besides this, performance of CG-OLET is investigated and additionally, mathematical model for cylindrical gate OLET is described. The DG-OLET is realized that helps in higher charge carrier modulation in OSC channel layer, whereas Cylindrical -OLET will be utilized in wearable electronics for medical and space technology applications.