Abstract: The semiconductor light emitting device includes a semiconductor substrate (1), a first conductivity type first cladding layer (2) deposited on the semiconductor substrate (1), an active layer (4) deposited on the first cladding layer (2), and the second conductivity type second cladding layer (6) deposited on the active layer (4). The first and the second cladding layers (2, 6) are made of the II/VI-compound semiconductors including at least one kind of II group elements such as Zn, Hg, Cd, Mg and at least one kind of VI group elements such as S, Se, Te. The lattice mismatching .DELTA.a/a (%) between at least one of the first cladding layer (2) and the second cladding layer (6) and the substrate is set within the range of -0.9%.ltoreq..DELTA.a/a.ltoreq.0.5% (reference symbols a and a.sub.c represent the lattice constant of the semiconductor substrate and the lattice constant of at least either of the first and second cladding layers, and .DELTA.a is obtained from .DELTA.a=a.sub.c -a).

Abstract: The semiconductor light emitting device includes a semiconductor substrate (1), a first conductivity type first cladding layer (2) deposited on the semiconductor substrate (1), an active layer (4) deposited on the first cladding layer (2), and the second conductivity type second cladding layer (6) deposited on the active layer (4). The first and the second cladding layers (2, 6) are made of the II/VI-compound semiconductors including at least one kind of group II elements such as Zn, Hg, Cd, Mg and at least one kind of group VI elements such as S, Se, Te. The lattice mismatching .DELTA.a/a (%) between at least one of the first cladding layer (2) and the second cladding layer (6) and the substrate is set within the range of -0.9%.ltoreq..DELTA.Aa/a.ltoreq.0.5% (reference symbols a and a.sub.c represent the lattice constant of the semiconductor substrate and the lattice constant of at least either of the first and second cladding layers, and .DELTA.a is obtained from .DELTA.a=a.sub.c -a).

Abstract: A semiconductor laser using a II-VI compound semiconductor as the material for cladding layers, capable of emitting a blue to green light is disclosed. In an aspect of the semiconductor laser, an n-type ZnSe buffer layer, an n-type ZnMgSSe cladding layer, an active layer made of, for example, ZnCdSe, a p-type ZnMgSSe cladding layer and a p-type ZnSe contact layer are stacked in sequence on an n-type GaAs substrate. A p-side electrode such as an Au/Pd electrode is provided in contact with the p-type ZnSe contact layer. An n-side electrode such as an In electrode is provided on the back surface of the n-type GaAs substrate. In another aspect of the semiconductor laser, an n-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the n-type ZnMgSSe cladding layer and the active layer, and a p-type optical guiding layer made of ZnSSe, ZnMgSSe or ZnSe is provided between the p-type ZnMgSSe cladding layer and the active layer.

Abstract: A semiconductor laser capable of emitting blue or green light is disclosed. The semiconductor laser comprises an n-type ZnMgSSe cladding layer, an active layer, a p-type ZnMgSSe cladding layer, a p-type ZnSe contact layer and a p-type ZnTe contact layer which are stacked in this sequence on an n-type GaAs substrate. A p-side electrode is provided on the p-type ZnTe contact layer. An n-side electrode is provided on the back surface of the n-type GaAs substrate. A multiquantum well layer comprising quantum wells made of p-type ZnTe and barriers made of p-type ZnSe is provided in the depletion layer produced in the p-type ZnSe contact layer along the junction interface between the p-type ZnSe contact layer and the p-type ZnTe contact layer. Holes injected from the p-side electrode pass through the junction by the resonant tunneling effect through quantum levels formed in the quantum wells of the multiquantum well layer.

Abstract: A semiconductor laser has a first cladding layer of a first conductivity type, an active layer, and a second cladding layer of a second conductivity type, which are successively deposited on a semiconductor substrate by epitaxial growth. The first cladding layer and/or the second cladding layer is made of a compound semiconductor material of a zincblende crystal structure containing Mg.

Abstract: A light emitting device has a transparent substrate, a substantially transparent first electrode layer formed on the transparent substrate, a phosphor layer formed on the first electrode layer, a second electrode layer formed on the phosphor layer, an insulating layer formed on the second electrode layer, and a third electrode layer formed on the insulating layer. A hot electron is generated by the application of a voltage to the second and third electrode layers, and the light emitting device is energized to become luminuous by injecting the hot electron thus generated into the phosphor layer.

Abstract: A double heterojunction II-VI group compound semiconductor laser has a substrate of GaAs or Gap, a first cladding layer, an active layer, and a second cladding layer which are successively deposited on the substrate by way of epitaxial growth. One or both of the first and second cladding layers have a composition of ZnMgSSe.

Abstract: A method of producing a p-type CdS wherein oxygen is doped into a CdS layer at a concentration in a range between 10.sup.16 and 10.sup.19 atomic/cm.sup.3.

Abstract: In a flame detecting apparatus for detecting the flame of fire or the like using a sensor 1, a signal processing unit 3 includes a span counting section 5 for dividing a time base into several time spans, each having a predetermined time interval, and counting the number of signals output from the sensor 1 as a count value for each span, a count value storage section 6 for storing the count value for each span output from the span counting section 5, and an calculation section 7 for judging the occurrence of flame by taking into account the count values counted for the past spans which have been stored in the count value storage section 6, as well as the count value of the latest span, when the count value of the latest span is output from the span counting section 5.