چکیده:
In this work, we are studied the effect of carbon nano-particles (CNP) doping of an active layer on the electrical properties of P3HT/PVA organic field effect transistor (OFET). A top gate-bottom contact (TG-BC) configuration was used to fabricated an organic field effect transistor with Poly (3-hexylthiophene-2,5-diyl (P3HT)) (as pure and doped with CNP) as an active layer, and polyvinyl alcohol (PVA) as a dielectric layer the gate electrode. OFET was made with AL/PVA/ (P3HT:% CNP) /Au structure, by using masks and required instrument which were manufactured in lab, in a constant conductance channel width and length (W=1mm, L= 60 µm). The dielectric layer of polyvinyl alcohol (PVA) was deposited by spin coating method, which its electrical capacity per unit area at AL/PVA/Au sandwich structure is (Ci=223 nF/cm2). While the semiconducting polymer was deposited by spin coating method to (203nm) as active layer thickness.
The Atomic Force Microscopy-AFM was used to investigate the surface properties of thin films of the pure and doped P3HT with CNPs. The surface nature and the size and distribution of grains for thin films were examined for pure and doped P3HT polymeric with two ratios (1% , 5%) of carbon nanoparticles (CNPs) , to see the effect of conformation, using an atomic force microscope device. The results shows affects the surface structural properties of synthetic thin films, as they reduce crystal volumes, increase the number of crystals formed and redistribute the formed crystals, In general, the pure and doped seems a semi-crystalline films, and each less surface roughness and Rq at additive ratio 1% and increase at 5% CNPs, according to the results of the AFM.
The results shown that all devices were operating in enhancement (accumulation) mode. The calculation of OFET some parameters was done after measurement of output and transfer characterizations. The results of the saturation mobility and the ratio Ion/Ioff and the threshold voltage were be influenced with doping of semiconductor layer, due to the changing of the resistance of the conduction channel. The best characteristic of the organic field effect transistor is when the doping ratio of an active layer 3% of CNP, which has the highest saturation mobility value (1. 41x10-1 cm2/Vs) and (Ion/Ioff= 199) , and threshold voltage (-1. 2V).
خلاصه ماشینی:
com ABSTRACT: In this work, we are studied the effect of carbon nano-particles (CNP) doping of an active layer on the electrical properties of P3HT/PVA organic field effect transistor (OFET).
A top gate-bottom contact (TG-BC) configuration was used to fabricated an organic field effect transistor with Poly(3-hexylthiophene-2,5-diyl (P3HT)) (as pure and doped with CNP) as an active layer, and polyvinyl alcohol (PVA) as a dielectric layer the gate electrode.
Keywords: Organic field effect transistor OFET, Poly(3-hexylthiophene-2,5-diyl) (P3HT), Polyvinyl alcohol (PVA), CNP, Thin film, Mobility, AFM, Threshold voltage, Channel resistant.
[10-12] The performance of an organic field effect transistor is determined by finding the parameters associated with this device which are the mobility (µ) of the charge carrier in conductive channel, the (Ion / Ioff) ratio and the threshold voltage (Vth) and others, whose value can be determined from the typical properties obtained when measuring the electrical properties of these devices (output and transfer characteristics).
Results & Discussion: The surface nature and the size and distribution of grains for thin films were tested for pure and doped P3HT polymeric with two ratios (1%, 5%) of carbon nanoparticles (CNPs), to see the effect of conformation, using an atomic force microscope device.
{مراجعه شود به فایل جدول الحاقی} Figures (4) to (8) show the results of the measurement; (a) the output characteristic and (b,c) transfer characteristic of these organic transistors, which shows that the doping of the active layer with various ratio of CNP in the transistor configuration has a significant effect on the electrical properties of this device.