Abstract:
The disclosure presents a method of growing large crystals of GaP from solution in which a zone of liquid gallium saturated with GaP is passed upward through a GaP feed ingot. In order to grow large crystals, it was found necessary to initiate growth onto a twinned seed crystal in which all of the twin planes are parallel to each other and parallel to a growth direction. Wafers cut parallel to the twin planes exhibit a (111) surface which are suitable for electroluminescent devices.
Abstract:
GREEN-EMITTING ELECTROLUMINESCENT GALLIUM PHOSPHIDE DIODES ARE GROWN BY LIQUID PHASE EPITAXY. A GA-GAP MELT CONTAINED IN A COVERED CRUICIBLE IS PLACED IN A VERTICAL FURNACE. A GAP SUBSTRATE WAFER IS INSERTED INTO THE MELT WHICH HAS BEEN MAINTAINED AT A TEMPERATURE OF ABOUT 1110-1140*C. AN N-TYPE GAP LAYER IS PRODUCED BY THE ADDITION OF A DOPANT SELECTED FROM S, SE, AND TE TO THE MELT WHICH IS SLOWLY COOLED TO A TEMPERATURE OF ABOUT 1070-1100*C., AT WHICH TIME THE MELT IS COUNTERDOPED WITH AN ACCEPTOR DOPANT, E.G., ZN OR CD. THE MELT IS FURTHER COOLED TO ABOUT 1030-1060*C., CAUSING THE GROWTH OF A P-TYPE LAYER, AFTER WHICH THE SUBSTRATE IS REMOVED FROM THE METAL AND FURTHER COOLED TO AMBIENT TEMPERATURES. ELECTROLUMINESCENT DIODES ARE THEN PREPARED BY THINNING THE SUBSTRATE SIDE OF THE WAFER TO REDUCE SERIES RESISTANCE. AU-ZN AND AU-SN ALLOY DOTS ARE APPLIED TO THE P AND N SIDE RESPECTIVELY, OF SAWED OR CLEAVED SECTIONS OF THE WAFER. GREEN-EMITTING DIODES PREPARED BY THE ABOVE METHOD HAVE EFFICIENCIES OF ABOUT 2.7X10-4, WHICH EFFICIENCIES CAN BE IMPROVED BY A FACTOR OF 2 OR MORE BY COATING THE DIODES WITH ANTI-REFLECTIVE EPOXY COATINGS. THE DIODES FIND UTILITY AS PANEL INDICATORS.
Abstract:
METHOD OF PREPARING "-Al2O3 .beta."-Al2O3 is a highly desirable material for serving the double function of solid electrolyte and separator in a rechargeable battery that employs sodium, Na, as the anode and sulfur, S, as the cathode. But conventional means for manufacturing the .beta."-Al2O3 require temperatures between 1400 and 1600.degree.C. By reacting .theta.-Al2O3 with Na2O, or a compound that yields Na2O on decomposition, the desired .beta."-Al2O3 is obtained at temperatures as low as 950.degree.C.
Abstract:
beta ''-Al2O3 is a highly desirable material for serving the double function of solid electrolyte and separator in a rechargeable battery that employs sodium, Na, as the anode and sulfur, S, as the cathode. But conventional means for manufacturing the beta ''-Al2O3 require temperatures between 1400 DEG and 1600 DEG C. By reacting theta -Al2O3 with Na2O, or a compound that yields Na2O on decomposition, the desired beta ''-Al2O3 is obtained at temperatures as low as 950 DEG C.