Original scientific paper
Photoconduction of mixed organic crystals of naphthalene doped with anthracene impurity
Muhammad Saleh
; Department of Physics, Bahauddin Zakariya University, Multan, Pakistan
Ahmed Tahir Naveed
; Department of Physics, Bahauddin Zakariya University, Multan, Pakistan
Abstract
Mixed organic crystals of naphtbalene doped with varying concentrations of anthracene impurity were grown from the melt, following extensive purification efforts in specially designed crystal growing tubes. Such crystals grow with the plane of maximum growth corresponding to the „ab“ crystallographic plane, and cleave readily in this plane. A simple technique for determining impurity concentration ~ ppm along the said mixed crystals is described in detail. The spectral response of photoconduction of mixed organic crystals of naphthalene doped with anthracene impurity ~ 1 ppm is divided into two regions. The one at 350 nm is similar to that of anthracene and the photocarrier generation is related with the weak n-π* transition of the anthracene impurity in the said crystals and the polarity for radiations which induce n-π* excitations in the wavelength region of 200 nm to 320 nm. In n-π* excitation region, the photocurrent with the illuminated electrode positive is much larger than that with the illuminated electrode negative.
Keywords
Hrčak ID:
331801
URI
Publication date:
8.4.1991.
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