STUDIES ON SOME HETEROJUNCTIONS
Alaa El-Din Abdel Halim Mohamed Farag;
Abstract
The structural properties of chlorophyll either in a powder form or in a thin film fonn prepared by spray technique were investigated using the X-ray diffraction technique . It was found throughout tllis investigation that chlorophyll has amorphous nature because of the presence of the long- chain phytol.
The optical transmission measured in dark at normal incidence of light scanning double beam spectrophotometer showed that there are two absorption peaks at 41 0&680run
The graphical representation of log p as a function of_!_ for
T
chlorophyll thin films (of the different thicknesses ) yields a straight line in the temperature range of (31 0-370 K) indicating the existance of one conduction mechanism.
The obtained activation energy of the free charge carriers can be attributed to the existance of an acceptor level -1 e V above the
/ valence band.
Throughout the invistigation of the Seebeck coefficient S (thennoelectric power) , it was found that S in case of chlorophyll is positive indicating that chlorophyll thin film is a p- type semiconductor. It was found that S increase gradually with increasing temperature.
Graphical representation of S vs _!_ for chlorophyll thin films
T
yields to straight line indicating also the existance of one conduction mechanism in hannony with that predicted throughout the temperature dependence of the dark electrical resistivity.
The optical transmission measured in dark at normal incidence of light scanning double beam spectrophotometer showed that there are two absorption peaks at 41 0&680run
The graphical representation of log p as a function of_!_ for
T
chlorophyll thin films (of the different thicknesses ) yields a straight line in the temperature range of (31 0-370 K) indicating the existance of one conduction mechanism.
The obtained activation energy of the free charge carriers can be attributed to the existance of an acceptor level -1 e V above the
/ valence band.
Throughout the invistigation of the Seebeck coefficient S (thennoelectric power) , it was found that S in case of chlorophyll is positive indicating that chlorophyll thin film is a p- type semiconductor. It was found that S increase gradually with increasing temperature.
Graphical representation of S vs _!_ for chlorophyll thin films
T
yields to straight line indicating also the existance of one conduction mechanism in hannony with that predicted throughout the temperature dependence of the dark electrical resistivity.
Other data
| Title | STUDIES ON SOME HETEROJUNCTIONS | Other Titles | دراسات على بعض الوصلات المتغايرة | Authors | Alaa El-Din Abdel Halim Mohamed Farag | Issue Date | 1997 |
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