Influence of surface structure and morphology of PEDOT: PSS on its optical and electrophysical characteristics

2021 ◽  
Vol 103 (3) ◽  
pp. 93-100
Author(s):  
А.К. Aimukhanov ◽  
◽  
X.S. X.S. Rozhkova ◽  
А.К. Zeinidenov ◽  
Т.E. Seisembekova ◽  
...  

This paper presents the results of a study of the effect of modification of the structure of the PEDOT: PSS polymer with hole conductivity on the optical and electrophysical properties of an organic solar cell. It was found that the modification of a polymer film with ethyl and isopropyl alcohols leads to a change in the morphology and roughness of the film surface. It has been determined that annealing of films in alcohol vapor promotes the formation of more uniform films. It is shown that upon modification of the PEDOT: PSS film in alcohol vapor the absorption spectrum shifts the absorption maximum of PEDOT to the short-wavelength region of the spectrum, the absorption of the aromatic PSS fragment decrease. X-ray phase analysis showed that after surface modification with alcohol vapor, the PEDOT and PSS chains change their structure. It is shown that the structural features of the surface morphology of PEDOT: PSS affect the electrophysical parameters of the films, such as the effective extraction rate and the effective time of flight of charge carriers. It was found that the modification of the surface of the PEDOT: PSS film leads to an improvement in the electrical transport properties of the films.

2021 ◽  
Author(s):  
Dongha Shin ◽  
Hwa Rang Kim ◽  
Byung Hee Hong

Since of its first discovery, graphene has attracted much attention because of the unique electrical transport properties that can be applied to high-performance field-effect transistor (FET). However, mounting chemical functionalities...


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 746
Author(s):  
Meiling Hong ◽  
Lidong Dai ◽  
Haiying Hu ◽  
Xinyu Zhang

A series of investigations on the structural, vibrational, and electrical transport characterizations for Ga2Se3 were conducted up to 40.2 GPa under different hydrostatic environments by virtue of Raman scattering, electrical conductivity, high-resolution transmission electron microscopy, and atomic force microscopy. Upon compression, Ga2Se3 underwent a phase transformation from the zinc-blende to NaCl-type structure at 10.6 GPa under non-hydrostatic conditions, which was manifested by the disappearance of an A mode and the noticeable discontinuities in the pressure-dependent Raman full width at half maximum (FWHMs) and electrical conductivity. Further increasing the pressure to 18.8 GPa, the semiconductor-to-metal phase transition occurred in Ga2Se3, which was evidenced by the high-pressure variable-temperature electrical conductivity measurements. However, the higher structural transition pressure point of 13.2 GPa was detected for Ga2Se3 under hydrostatic conditions, which was possibly related to the protective influence of the pressure medium. Upon decompression, the phase transformation and metallization were found to be reversible but existed in the large pressure hysteresis effect under different hydrostatic environments. Systematic research on the high-pressure structural and electrical transport properties for Ga2Se3 would be helpful to further explore the crystal structure evolution and electrical transport properties for other A2B3-type compounds.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3222
Author(s):  
Kamil Goc ◽  
Janusz Przewoźnik ◽  
Katarzyna Witulska ◽  
Leszek Chlubny ◽  
Waldemar Tokarz ◽  
...  

A study of Ti3Al1−xSixC2 (x = 0 to x = 1) MAX-phase alloys is reported. The materials were obtained from mixtures of Ti3AlC2 and Ti3SiC2 powders with hot pressing sintering technique. They were characterised with X-ray diffraction, heat capacity, electrical resistivity, and magnetoresistance measurements. The results show a good quality crystal structure and metallic properties with high residual resistivity. The resistivity weakly varies with Si doping and shows a small, positive magnetoresistance effect. The magnetoresistance exhibits a quadratic dependence on the magnetic field, which indicates a dominant contribution from open electronic orbits. The Debye temperatures and Sommerfeld coefficient values derived from specific heat data show slight variations with Si content, with decreasing tendency for the former and an increase for the latter. Experimental results were supported by band structure calculations whose results are consistent with the experiment concerning specific heat, resistivity, and magnetoresistance measurements. In particular, they reveal that of the s-electrons at the Fermi level, those of Al and Si have prevailing density of states and, thus predominantly contribute to the metallic conductivity. This also shows that the high residual resistivity of the materials studied is an intrinsic effect, not due to defects of the crystal structure.


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