China
Africa
Explore chapters and articles related to this topic
Polymer Semiconductors
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Tariq Altalhi, Polymers in Energy Conversion and Storage, 2022
Moises Bustamante-Torres, Jocelyne Estrella-Nuñez, Odalys Torres, Sofía Abad-Sojos, Bryan Chiguano-Tapia, Emilio Bucio
Most polymers are good electrical insulators; however, they can have the mobile charge carriers redistributed according to the applied electric field’s intensity and period. In some cases, the direct current conductivity applied under high electric fields may have resulted from impurities (Glowacki et al. 2012). Charge carriers are called electrons or holes. The nature and role of charge carriers will depend on the direct relationship between the structure, morphology, and transport of the studied system (Jaiswal and Menon 2006). The continuous development of organic semiconducting polymers plays a vital role in the manufacture of various electronic devices such as OTFTS, OPVs, and organic light-emitting diodes (OLEDs) (Sirringhaus 2014; Paterson et al. 2018).
Electrochemical Sensing via Porous Materials
Published in Antonio Doménech-Carbó, Electrochemistry of Porous Materials, 2021
In principle, all electrodes displaying electrocatalytic activity can be seen as signal amplifiers. A correlation between electrochemistry and electronics is obtained through field effects sensors and biosensors. In these devices, there is electrostatic modulation of charge carrier mobility in suitably prepared semiconductors. In gate electrodes, there is conductance modulation through the electrostatic environment of the semiconductor surface exposed to the target solution.
From Insulating to Conducting Polyimides
Published in Andreea Irina Barzic, Neha Kanwar Rawat, A. K. Haghi, Imidic Polymers and Green Polymer Chemistry, 2021
Göknur Dönmez, Ayça Ergün, Merve Okutan, Hüseyin Deligöz
Let’s explain the conductivity phenomenon for a polymer. The conductivity of an insulating material like polymers depends on the charge (q), quantity/concentration (N), and mobility (μ) of the charge carriers as shown in eq 4.5. A charge carrier may be a hole, an electron, an ion, or a polar group that allows the transport and movement of the electrical charge. These charge carriers tend to randomly move in the absence of an electrical field. In order to increase the conductivity, it is necessary to raise the amount of charge carriers in the insulating component and ensure their mobility. σ=∑Nqμwhere σ is the conductivity, N is the concentration or quantity, q is the charge number and the μ is the mobility of the charge carriers.
Dielectric and electro-optical properties of nematic liquid crystal p-methoxybenzylidene p-decylaniline dispersed with oil palm leaf based porous carbon quantum dots
Published in Journal of Dispersion Science and Technology, 2023
Ayushi Rastogi, Pankaj Kumar Tripathi, Tarsh Manohar, Rajiv Manohar
Here, is the pre exponential factor and Ea is the activation energy. The increased conductivity observed for OPL QDs composite systems suggests that the energy barrier gets reduced for these composites as compared to pure MBDA LC which increases the probability of hopping between two favorite sites. The influence of conduction mechanism is not usually observed at low temperature due to the fact that at low temperature there is existence of two phenomenons. Firstly, the reduction of free charges and secondly, at low temperature the thermal energy is not sufficient to allow hopping between favorite sites. However, at increased temperature there is a growth in the hopping mechanism and mobility of charge carriers. Generally, in thermally activated hopping mechanism the mobility is given by following relation[17,18]:
The Hall current effect of magnetic-optical-elastic-thermal-diffusive semiconductor model during electrons-holes excitation processes
Published in Waves in Random and Complex Media, 2022
Shreen El-Sapa, Kh. Lotfy, Alaa A. El-Bary
In modern physical studies, moving charge carriers are free of particles, yet they carry electric charges and this is clearly shown during the study of semiconductors. There are many charge carriers such as electrons, ions, and holes. In semiconductor material electrons and holes are charge carriers. At absolute temperatures, the free electrons in the atoms of the semiconductors are present in the lower levels (the valence energy band). In this case, the electrons cannot move or move from one place to another, and the electric current cannot flow. Since the internal resistance of semiconductors decreases with increasing temperature, and with the gradual temperature rise, some electrons can jump from the valence band to the conduction band. In this case, with the movement of electrons, a flow of electric current is created. With each transition of an electron into the conduction band, there will be a hole in the valence band. Therefore, electrons and holes are adjacent in semiconductors. In any case, the electric current created in a semiconductor is caused by the free electrons. In some special cases where the material is exposed to gradient temperatures, the holes also transmit electric current.
Effect of different dosage of gamma irradiation on quasi-solid-state conducting polymer electrolyte and its application as high performance dye-sensitized solar cells
Published in Radiation Effects and Defects in Solids, 2021
K. M. Manikandan, A. Yelilarasi
Figure 5(a) shows the electrical conductivity as a function of temperature for γ-ray-irradiated nanocomposite polymer electrolyte. The electrical conductivity of an unirradiated polymer electrolyte is 0.658 S cm−1. It is seen that the electrical conductivity increases with irradiation dose (Table 2). A high electrical conductivity of 0.686 S cm−1 is observed in the 15 Gy γ-ray-irradiated polymer electrolyte. It reveals that the possibility of the scission of long polymer chain into the short polymer segments by the exposure of γ-ray irradiation, which leads to an amorphocity of the polymer matrix (15). The temperature dependence of an electrical conductivity of the polymer electrolytes is correlated with the activation energy by Arrhenius plot (Figure 5(b)). It can be seen that the increase in electrical conductivity with an elevated temperature is due to the mobility of the charge carriers (22). The calculated values of activation energy, Ea are summarized in Table 1. Furthermore, the obtained result exhibits the maximum electrical conductivity of an optimized γ-ray-irradiated polymer electrolyte (15 Gy) with minimum activation energy (0.664 kJ mol−1).