A small-molecule organic semiconductor

Abstract

The electrical conductivity and optical properties of the bis-diethylaminokumarin have been investigated. The electrical conductivity of the compound exhibited three-dimensional hopping conduction in the temperature range 295−321 K. The compound shows typical semiconductor property and its semiconducting property results from delocalization of the π-electrons in the structure. To determine the optical band gap of the compound, an optical absorption study was made in the wavelength range 250−600 nm. The optical study revealed that the optical transition is the allowed indirect one. The electronic parameters such as electrical conductivity at room temperature σ 25 , activation energy E, and optical band gap Eg , of the compound are 1.46 · 10 −5 S/cm, 0.42 eV and 2.46 eV, respectively. These values are in agreement with electronic parameters of organic semiconductors.

Optical Properties of ZnO Nanoparticles Synthesised from a Polysaccharide and ZnCl2

“…It is also assumed that the absorption coefficient near the band edge shows an exponential dependence on photon energy and this dependence is given as follows [15,16]:…”

Evaluation by tunneling effect for the temperature-dependent electric conductivity of polymer-carbon fiber composites with visco-elastic properties

“…In VRH, electron hopping occurs predominantly beyond nearest neighbors. 13,14,17,27 The VRH model for the conductivity is given by…”

“…The value of T 0 at 4300 K was estimated from the slope of the straight line. The value of N(E F ) was calculated to be 4.77 Â 10 22 eV À1 cm À3 , assuming a value of 10 À7 cm for 1/a from Yakuphanoglu et al 27 Figure 3g shows the hopping distance R (as a solid curve) and the average hopping energy W (as a dashed curve) as a function of T. The value of R decreased with temperature, whereas the value of W increased with the temperature, as has been reported for many materials. The temperature-dependent R values were greater than those of MWNTs 17 and La 0.67 Ca 0.33 MnO 3 perovskite Tunneling effect in polymer-carbon fiber composites magnetite.…”

“…Mott's VRH analysis is completely appropriate for semiconducting phases such as TiO 2 doped by Co, Cr, Cd, Ce and Fe, 14 and the widespread application of VRH to doped semiconductors, amorphous conductors, glasses and conductive and semi-conductive polymers has also been successful. [14][15][16][17][24][25][26][27] However, composite systems consisting of conductive or semi-conductive fillers embedded in insulating polymers do not lie within Mott's VRH framework. This paper mainly focuses on two features in modeling electron transport:…”

Synthesis, structural, spectral, optical characterizations of (3-cyano-9-methyl-5-oxo-1, 5-dihydro-2H-chromeno [4,3-b] pyridin-2-ylidene) propanedinitrile (CMOCPP) and its photodiode application

“…Study of the optical absorption of new synthetic organic materials, particularly the absorption edge has proved to be very useful for elucidation of the electronic structure of these materials and the determination of optical and electrical characteristics is of considerable importance for applications in optoelectronic devices [14].…”