Showing papers on "Lead telluride published in 1983"

The effect of phonon-grain boundary scattering, doping and alloying on the lattice thermal conductivity of lead telluride

Abstract: The lattice thermal conductivity of lead telluride has been investigated theoretically as a function of grain size, level of doping and alloying. Although there is some difficulty in making predictions of the precise dependence of the lattice thermal conductivity on these parameters, it is possible to indicate the range over which the results may vary. It is concluded that for moderately doped material having a grain size of 1 mu m the reduction in lattice thermal conductivity would lie in the range 4-6% for unalloyed lead telluride and 11-13% for highly disordered alloys.

Light sink layer for a thin-film EL display panel

Abstract: A thin-film electroluminescent (EL) panel operating as a matrix-addressed display is provided with a light sink layer immediately behind the phosphor layer thereof to enhance the legibility of the display under high ambient light conditions The light sink layer is formed of a p-type semiconductor compound material comprised of 20% lead telluride and 80% cadmium telluride doped with indium The addition of the indium into the material introduces free electrons which compensate for the hole carriers therein and thereby increases the specific resistivity of the material The addition of lead into the semiconductor compound material forms the lead telluride which in combination with the cadmium telluride reduces the energy band gap of the material to effectively absorb the ambient light in the visible range which is the source of the bad legibility Moreover, the lead serves to reduce the mobility of the free charge carriers in the material and thereby further increases the specific resistivity of the material Thus, the combined effects of the indium and the lead provide the semiconductor compound material with a specific resistivity in the range of 10 8 to 10 12 ohm-centimeter Such a high specific resistivity material for the light sink layer is especially useful in enabling the EL panel to operate with a relatively steep luminance vs voltage characteristic curve as required for multiplexing operation of the matrix-addressed EL panel

Temperature dependence of the figure of merit of improved thermoelectric materials based upon lead telluride

Abstract: The effect of a reduction in lattice thermal conductivity, due to phonon-grain boundary scattering, on the thermoelectric figure of merit of highly disordered alloys of lead telluride has been investigated as a function of temperature and for three different carrier concentrations. It is concluded that the figure of merit of material with a mean grain size of approximately 1 mu m is about 10% higher than equivalent 'single crystal' or large grain size material.

Impurity doping method

Abstract: PURPOSE:To control impurity concentration accurately when an n gtowth layer to which Te is added is obtained by using a compound of a IV group element and Te as an impurity raw-material and doping Te to a growth layer. CONSTITUTION:When the n type growth layer in which Te is added onto a semiconductor substrate is acquired through a liquid phase epitaxial growth method, the compound of the IV group element and Te is used as the impurity raw- material. A substance such as tin telluride (SnTe) or lead telluride (PbTe) is used as the compound of the IV group element and Te. Weighing is facilitated owing to the atomic weight of the IV group element. The electron concentration of a Ga0.5Al0.5As growth layer in the case when Ga, Al or GaAs as the impurity and 0.133mg SnTe as a growth raw-material are liquid-grown on the substrate is 1X10 cm , a very small amount of approximately 0.067mg mush be added when a metal Te is used as the impurity raw-material in order to obtain the same electron concentration, and weighing and addition are facilitated up to approximately twice when SnTe is used as the raw material. The crystallinity, surface homology, etc. of the n type growth layer grown while employing SnTe as the raw material are quite the same as those of a layer using the metal Te.