Abstract: A crystal solution growth method for growing a crystal by providing a temperature difference between the higher and lower regions of a solvent, and disposing a source crystal at a high temperature region of the solution and a seed crystal at a low temperature region of the solution. The crystal solution growth method includes the steps of: placing the seed crystal on a recess of a heat sink, the heat sink being disposed under the solvent and the recess being defined on the top surface of the heat sink; placing a seed stopper on the seed crystal to fix the seed crystal, the seed stopper having a tubular part with an inner diameter generally same as the seed crystal and a seed crystal fixing part for fixing the seed crystal formed at one end of, the tubular part on the seed crystal side; and forming a temperature difference between the higher and lower regions of the solvent and growing a crystal oil the surface of the seed crystal.

Abstract: Group II-VI compound semiconductor crystal containing Zn as group II element or mixed crystal containing the compound semiconductor crystal is etched by an etchant made of H.sub.2 SO.sub.4 aqueous solution dissolved with potassium permanganate KMNO.sub.4. Preferably, an etchant is moved round in a cylindrical vessel by a stirrer, and group II-VI compound semiconductor wafers are held by a jig, disposed generally in parallel with the flow of the etchant, immersed into the etchant, and mirror-etched.

Abstract: A terminal equipment control system which controls the operation state of multiple terminals having data communication with master equipment. A control signal of a specified duration is output from the master equipment to each of a plurality of multiple terminals, and the duration of the each control signal is measured by a measuring device provided in each terminal such that the current operation state of each terminal is changed when the measurement by the measuring device becomes equal to or larger than the specified duration.

Abstract: A ZnSe source crystal is treated in a Se vapor pressure peaks are obtained when the Se pressure is 6 to 9 atoms dissolved in a Zn solvent to the saturation concentration at a high temperature portion in the solution. A ZnSe single crystal is grown on an underlie substrate placed at a low temperature portion in the solution. When the temperature of the vapor pressure treatment is 1050.degree. C., excellent photoluminescence peaks are obtained when the Se pressure is 6 to 9 atoms.

Abstract: A solution growth apparatus for conducting an epitaxial growth of a compound semiconductor crystal from solution by relying on the temperature difference technique at a constant growth temperature and on a mass production scale without deranging the control of the growth temperature applied externally of the growth apparatus and with the application of only a small heating power and only a small cooling power, by enhancing the thermal exchange efficiency through the provision of heating means, via an insulator, for the melt-containing reservoir provided on the growth boat housed within a quartz reactor and by the provision of cooling means at the bottom of the boat within the reactor.

Abstract: A method of forming a pn junction with a Group IIB-VIB compound semiconductor containing Zn is disclosed, the method including preparing an n type semiconductor region either locally or entirely in a Group IIB-VIB compound semiconductor crystal obtained by relying on a crystal growth method in liquid phase using a temperature difference technique, and subjecting this crystal to a thermal annealing in a Zn solution or in a Zn atmosphere to produce an n type region. Crystal growth is conducted while controlling the vapor pressure of the constituent Group IVB element to produce a p type region. A combination of all these steps gives a more stable pn junction.

Abstract: A light-responsive light-emitting diode display comprises a light-emitting diode circuit including a series connection of light-emitting diodes and a light-responsive current-controlling circuit connected in series to said light-emitting diode circuit for supplying a current thereto in correspondence with the ambient brightness. A unipolar photo-transistor can provide a current above a predetermined minimum value and increasing with the intensity of incident lights and can absorb excess voltages when applied. Light-responsive current-control reduces the useless power dissipation, and all solid-state display provides a very long service life.

Abstract: A plurality of light-emitting diodes are connected in series to elevate the working voltage. A plurality of said series connection are connected in parallel to maintain display even upon a disconnection accident. The total number of light-emitting diodes provides a bright and failure-safe colored light display at a low power consumption. The conventional colored-light-emitting display can be easily substituted by the novel light-emitting diode display to reduce the power consumption and elongate the service lifetime.

Abstract: A single crystal of gallium phosphide including 0.5 atomic ratio or less of indium is grown from a melt consisting of indium, gallium and phosphorous with an atomic ratio of gallium to phosphorous equal to at least 2.0.