A light detecting device includes a light absorbing layer configured to absorb light in a wavelength range from visible light to short-wave infrared (SWIR); a first semiconductor layer provided on a first surface of the light absorbing layer; an anti-reflective layer provided on the first semiconductor layer and comprising a material having etch selectivity with respect to the first semiconductor layer; and a second semiconductor layer provided on a second surface of the light absorbing layer. The first semiconductor layer has a thickness less than 500 nm so as to be configured to allow light to transmit therethrough in the wavelength range from visible light to SWIR.

A light-receiving device includes a light-receiving element formed on a main surface of a substrate, a light incidence surface formed on a side portion of the substrate at an acute angle or an obtuse angle with respect to the plane of the substrate and having an inclined surface forming one plane, and a lens for focusing light incident on the light-receiving element. The lens is disposed at a position where the light incident from the light incidence surface is reflected on a side of a back surface of the substrate.

Photodetectors are fabricated on GaAs substrate using dilute nitride technology for high speed-high-sensitivity operation for telecom and datacom applications for the wavelength ranges covering O-band (Original band: 1260 nm to 1360) to C-band (conventional band: 1530-1565 nm).

An inverted metamorphic multijunction solar cell including an upper first solar subcell, a second solar subcell and a third solar subcell. The upper first solar subcell has a first band gap and positioned for receiving an incoming light beam. The second solar subcell is disposed below and adjacent to, and is lattice matched with, the upper first solar subcell, and has a second band gap smaller than the first band gap. The third solar subcell is disposed below the second solar subcell, and is composed of a GaAs base and emitter layer so as to optimize the efficiency of the solar cell after exposure to radiation. In some implementations, at least one of the solar subcells has a graded band gap throughout its thickness.

A light-receiving device of an embodiment of the present disclosure includes a photoelectric conversion layer that includes a first compound semiconductor with a first conductivity type and absorbs a wavelength of an infrared region, a first semiconductor layer formed on the photoelectric conversion layer, and an insulation layer formed to surround the photoelectric conversion layer and the first semiconductor layer, the first semiconductor layer having a second conductivity-type region at a middle region excluding a periphery facing the photoelectric conversion layer.

A rotation angle encoder apparatus is disclosed. The rotation angle encoder apparatus may comprise a plurality of light sources, a plurality of light detectors, and a plurality of pinions rotatable about a shaft. Each of the pinions may comprises a plurality of teeth and a plurality of gaps. The rotation angle encoder apparatus may comprise a plurality of stacked configurations such that, when the shaft is rotated, transmissivity may be measured to determine or calculate at least one measurement, such as an angle of rotation, position, movement, distance, or other discernable measurement. The rotation angle encoder apparatus with a plurality pinions and associated measurable transmissivities may enable an optical spectrum analyzer to increase wavelength accuracy and improve resolution in optical measurements.

A semiconductor device comprises a substrate, one or more first III-semiconductor layers, and a plurality of superlattice structures between the substrate and the one or more first layers. The plurality of superlattice structures comprises an initial superlattice structure and one or more further superlattice structures between the initial superlattice structure and the one or more first layers. The plurality of superlattice structures is configured such that a strain-thickness product of semiconductor layer pairs in each superlattice structure of the one or more further superlattice structures is greater than or equal to a strain-thickness product of semiconductor layer pairs in superlattice structure(s) of the plurality of superlattice structures between that superlattice structure and the substrate. The plurality of superlattice structures is also configured such that a strain-thickness product of semiconductor layer pairs in at least one of the one or more further superlattice structures is greater than a strain-thickness product of semiconductor layer pairs in the initial superlattice structure.

A multijunction solar cell in accordance with an example implementation includes a growth substrate; a first solar subcell disposed over or in the growth substrate; a tunnel diode disposed over the first solar subcell; and a grading interlayer directly disposed over the tunnel diode; a sequence of layers of semiconductor material forming a solar cell disposed over the grading interlayer comprising a plurality of solar subcells. The multijunction solar cell also includes a first wafer bowing inhibition layer disposed directly over an uppermost sublayer of the grading interlayer, such bowing inhibition layer having an in-plane lattice constant greater than the in-plane lattice constant of the uppermost sublayer of the grading interlayer. A second wafer bowing inhibition layer is disposed directly over the first wafer bowing inhibition layer.

A semiconductor device includes: a first semiconductor structure; a second semiconductor structure on the first semiconductor structure; an active region between the first semiconductor structure and the second semiconductor structure, wherein the active region includes multiple alternating well layers and barrier layers, wherein each of the barrier layers has a band gap, the active region further includes an upper surface facing the second semiconductor structure and a bottom surface opposite the upper surface; an electron blocking region between the second semiconductor structure and the active region, wherein the electron blocking region includes a band gap, and the band gap of the electron blocking region is greater than the band gap of one of the barrier layers; a first aluminum-containing layer between the electron blocking region and the active region, wherein the first aluminum-containing layer has a band gap greater than the band gap of the electron blocking region; a confinement layer between the first aluminum-containing layer and the active region, wherein the confinement layer includes a thickness smaller than the thickness of one of the barrier layers; and a p-type dopant above the bottom surface of the active region and comprising a concentration profile comprising a peak shape having a peak concentration value, wherein the peak concentration value lies in the electron blocking region.

A semiconductor crystal substrate includes a crystal substrate that is formed of a material including one of GaSb and InAs, a first buffer layer that is formed on the crystal substrate and formed of a material including GaSb, and a second buffer layer that is formed on the first buffer layer and formed of a material including GaSb. The first buffer layer has a p-type conductivity, and the second buffer layer has an n-type conductivity.