تحضير البوليمر الموصل بولي (ارثوا - تولدين) ودراسة الخصائص البصرية والكهربائية له واستخدامه في تصنيع الخلايا الشمسية == PREPARATION OF CONDUCTING POLY (O - TOLUIDINE) AND STUDY OF ITS ELECTRICAL AND OPTICAL PROPERTIES FOR APPLICATION AS A SOLAR CELLS
Author name:
حسين فالح حسين اللعيبي
General topic:
Physics
Specific topic:
Physics
Degree:
Doctorate
University:
University Of Basrah - Faculty Of Education
Language:
Arabic
University location:
Basrah
First pages:
26T1996 - p.pdf
Abstract:
The present study include the preparation of poly (O - Toluidine), by the chemical polymerization, then doped with HCl, and P - toluene sulphonic acid.The polymer solution deposited on glass, interdigitated finger electrode, and silicon wafer by the use of spin coating technique, in order to study electrical and optical properties as well as electronic applications in the fabrication of solar cells. The prepared samples were treated thermally before the measurement took place. Addition, a study was made of the effect of dyes on solar cells, (RhB, Flu, CuPc, and PbPc ) deposited on poly(O - Toluidine) and doped by p - toluene sulphonic acid (POT - PTSA). The thickness of the samples is measured by the use of Ellipsometry spectroscopy. The polymer thin films prepared were analysized by the use of (FT - IR) and Raman spectroscopes to determine the functional groups of the chemical bonds. To identify the nature, the structure of the surfaces of the prepared samples and to measured the partial size of the grain Atomic force Microscopy AFM insistent were used. The optical properties of the thin films prepared were studied including recording the absorption spectroscopy for wavelengths of (300 - 900 nm). The absorption coefficient and the forbidden energy gap to transmission directly were measured as well as the refraction index (n), extinction coefficient (k), dielectric constant ε, as well as, the optical constant represented by single oscillator energy (Eo), dispersion energy (Ed), moment of dielectric constant (M - 1, M - 1 3), non linear optical susceptibility (χ3) were determined.The electric conductivity was studied and it was found that the thin films correlate with the ohmic behaviour at the measured volts range (1 - 100V) for the polymers (POT, POT - HCl, POT - PTSA, and POMA). The effect of the temperature on the electric properties of these thin films is also studied. The study shows that the electric conductivity increases with the increase of temperature, where all the samples were found to show a negative thermal coefficient of resistance which is a characteristics of semi - conductive material.The effect of doping with HCl and p - toluene solphonic acid on electric conductivity was studied and found to increase to (2.46x10 - 5 S.cm - 1) while the conductivity of the polymer doping with HCl increases to (7.59x10 - 6 S.cm - 1) compared to the pure polymer (1.49x10 - 7 S.cm - 1). This study shows that the activation energy in the pure polymer is (0.313eV) and decreases when the polymer was doped with PTSA, HCl to (0.211 eV) and (0.235 eV) respectively.For the electronic application of prepared polymers (POT, POT - HCl, POT - PTSA, and POMA) a solar cells were constricted by using n - type silicon wafers and different electrode from gold and aluminium. The optical properties of the solar cell under the effect of the light equivalent to that of the sun and which falls vertically on the sample were studied ; it is practically found that, the highest efficiency obtained is (2.55 %) for the polymer (POTPTSA). The effect of thickness on the solar cell efficiency is also studied where it is found that the highest efficiency is about (2.55%) at thickness (35 nm). The electric properties of the solar cell were studied at different intensity (10,25, 50, 100) mW/cm2 and the efficiency reaches its maximum (4.88) when the intensity of the incident light is equal to 10 mW/cm2. It is observed practically that the efficiency of all cells decreases when dyes are added to the polymer (POT - PTSA). The exposure of the solar cell of the polymer (POTPTSA) to normal weather conditions was tudied for more than two monthswhere it is observed that the cell efficiency falls from 2.55 to 1.18 after two weeks of exposure. Then it reached constant value of 0.88 for two months of time exposure
