Organic phototransistor based on poly(3-hexylthiophene)/TiO2 nanoparticle composite

Abstract

Light sensitive phototransistor based on the composite of poly͑3-hexylthiophene͒ and TiO 2 nanoparticles has been developed. The device shows a quick change in channel current under light exposure, which can be attributed to a positive shift of the threshold voltage, while no change in the field effect mobility and off current can be observed. The shift of the threshold voltage is induced by accumulated electrons trapped by the TiO 2 nanoparticles in the channel. The photosensitivity of the device has been found to be dependent on the concentration of TiO 2 nanoparticles, the incident wavelength and the voltage between the source and drain.

Enhancement of Hole Mobility of Poly(3‐hexylthiophene) Induced by Titania Nanorods in Composite Films

“…[ 8 , 9 ] A device with TiO 2 nanorods has been characterized under 370 nm UV light with different light intensities, as shown in Figure 3 d. It is worth noting that the current response of the device to light illumination is ∼ 10 times higher than that of the OTFT based on P3HT and TiO 2 nanoparticles reported in a previous paper. [8] The transfer curve shifts to a higher gate voltage horizontally with the increase of light intensity and the gate voltage change can be fi tted with the analytical model: [ 9 ] Δ V G = AI β , where A is a constant and β = 0.22. The shift of the transfer curve can be attributed to the accumulation of electrons in the embedded TiO 2 nanorods.…”

“…[ 1 ] Organic-inorganic nanocomposites are one type of advanced material for organic devices because of the expected synergy between the organic and inorganic components, which lead potentially to new physical properties of the composites and various applications in devices, including solar cells, [2][3][4][5][6] phototransistors, [7][8][9] memories, [ 10 ] and sensors. [ 11 ] The composites of a conjugated polymer such as poly(3-hexylthiophene) (P3HT) and inorganic nanoparticles, such as ZnO, TiO 2 , or CdSe, have been used in organic solar cells, and gratifying power conversion effi ciencies (PCEs) up to 3.8% have been obtained.…”

Highly photosensitive thin film transistors based on a composite of poly(3-hexylthiophene) and titania nanoparticles

“…Recently, we have reported a new type of OPT based on a composite film of P3HT and TiO 2 nanoparticles. 3 The device shows a quick change in channel current under light illumination, which can be attributed to a positive shift in the threshold voltage, while no change in the field effect mobility and off current can be observed. In addition, the device shows very stable performance under a light illumination, which is very important for its application.…”

Organic thin-film phototransistors based on poly(3-hexylthiophene)

“…al. adopted P3HT in composite form combined with TiO 2 nanoparticles demonstrating good photocurrent generation under white light illumination [11]. Finally, the UV light sensitivity of OTFTs based on P3HT has not yet been analyzed.…”