Electrical properties of TCNQ/V2O5 heterojunction
M. H. SAYYAD1,*
,
KH. S. KARIMOV1,2,
K. UL HASAN1,
A. ELAHI1,
M. SALEEM1,
KH. M. AKHMEDOV2,
Z. M. KARIEVA3
Affiliation
- GIK Institute of Engineering Sciences and Technology, Topi, N.W.F.P., 23460, Pakistan
- Physical Technical Institute of Academy of Sciences, Dushanbe, 734025, Tajikistan
- Tajik Technical University, Dushanbe, 734000, Tajikistan
Abstract
In this study the electrical properties of tetracyanoquinodimethane (TCNQ) and vanadium pentoxide 2 5 ( ) V O structured
composite were evaluated. The composite was formed by drop deposition of TCNQ film from solution in benzol on
preliminary deposited V O2 5 layer from its suspension in distilled water on Cu substrate. The sandwich Cu/V2O5/TCNQ/Ga
and the surface Cu/V2O5/TCNQ/Cu type samples were fabricated. Resistance-temperature relationships and voltagecurrent characteristics of the composite samples were measured by using conventional digital voltmeter and ammeter at the
temperature interval of 24 o
C – 102 o
C with an error of ± 0.5 %. It is observed that the DC electrical conductivity, nonlinearity of voltage-current characteristics of the samples and activation energy for the surface type samples are
temperature dependent. The surface type samples show quasi-linear resistance-temperature relationship, the temperature
coefficient of resistance is sufficiently large and at 24 o
C is equal to – 2.4 / o
C and non-linearity coefficient of V-I
characteristics is low (1.4), whereas the sandwich type samples exhibit non-linear resistance-temperature relationship,
higher non-linearity coefficient (2.3) of V-I characteristics, lower temperature coefficient of resistance (-2.1 / o
C ). Sandwich
type samples show small rectification behaviour, rectification ratio unlike to conventional semiconductors increases with
temperature.
Keywords
Organic semiconductor, Low molecular material, Tetracyanoquinodimethane, Vanadium pentoxide, Composite.
Citation
M. H. SAYYAD, KH. S. KARIMOV, K. UL HASAN, A. ELAHI, M. SALEEM, KH. M. AKHMEDOV, Z. M. KARIEVA, Electrical properties of TCNQ/V2O5 heterojunction, Optoelectronics and Advanced Materials - Rapid Communications, 2, 3, March 2008, pp.170-175 (2008).
Submitted at: Sept. 24, 2007
Accepted at: March 16, 2008