A device for producing electrical current. In one embodiment, the device comprises a stack of epitaxial layers (from a bottom surface): a p-doped semiconductor reflector layer, a p-doped semiconductor emitter layer, an n-doped semiconductor base layer, and an n-doped semiconductor window layer. A radioisotope source, disposed above or in contact with an uppermost layer of the stack, produces radioisotope decay particles or gamma rays that impinge the stack. The electrical current is produced between the first and second conductive regions by action of the radioisotope decay particles or the gamma rays on the emitter and base layers.

A method of making a single-photon detector includes growing an epitaxial multi-layer structure that includes a buffer layer, an absorption layer, a transition layer, a field control charge layer, a multiplication layer, an inversion layer, a migration layer, a window layer, and an Ohmic contact layer sequentially on a substrate. A curved diffusion region is formed in the window layer and the Ohmic contact layer via a diffusion process. A mesa structure is formed by etching the epitaxial multi-layer. A light input window is formed on the substrate. A p-type electrode is formed on the Ohmic contact layer, and an n-type electrode is formed on the substrate. The inversion layer provides supplementary regulation of an electric field distribution that is regulated by the field control charge layer. A single-photon detector made from the method, and a single-photon detector array made with a multitude of the single-photon detectors are also provided.

A photoconductive transducer intended to generate or detect waves in the terahertz frequency domain or in the picosecond pulse domain is provided. The transducer comprises a three-dimensional structure that includes, in this order, a first planar electrode, an array of nano-columns embedded in a layer of resist and a second planar electrode parallel to the first planar electrode. The design of the transducer increases the optical-to-terahertz conversion efficiency by means of photonic and plasmonic resonances and by means of high and homogeneous electric fields. The height of the nano-columns as well as the thickness of the resist range between 100 nanometres and 400 nanometres. The width of the nano-columns is between 100 nanometres and 400 nanometres, the distance between two adjacent nano-columns is between 300 nanometres and 500 nanometres, the nano-columns are made of a III-V semiconductor. The second electrode is transparent, so as to allow the transmission of a laser source towards the photo-absorbing nano-columns.

The present invention relates to a semiconductor laser for use in an optical module for measuring distances and/or movements, using the self-mixing effect. The semiconductor laser comprises a layer structure including an active region (3) embedded between two layer sequences (1, 2) and further comprises a photodetector arranged to measure an intensity of an optical field resonating in said laser. The photodetector is a phototransistor composed of an emitter layer (e), a collector layer (c) and a base layer (b), each of which being a bulk layer and forming part of one of said layer sequences (1, 2). With the proposed semiconductor laser an optical module based on this laser can be manufactured more easily, at lower costs and in a smaller size than known modules.

A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.

After sequentially forming a first multilayer structure comprising a first set of semiconductor layers suitable for formation of a photodetector, an etch stop layer and a second multilayer structure comprising a second set of semiconductor layers suitable for formation of a light source over a substrate, the second multilayer structure is patterned to form a light source in a first region of the substrate. A first trench is then formed extending through the etch stop layer and the first multilayer structure to separate the first multilayer structure into a first part located underneath the light source and a second part that defines a photodetector located in a second region of the substrate. Next, an interlevel dielectric (ILD) layer is formed over the light source, the photodetector and the substrate. A second trench that defines a microfluidic channel is formed within the ILD layer and above the photodetector.

A flexible sensor module, includes: a sensing unit formed on a first substrate so as to be exposed to the outside, and configured to measure external environment information; a solar cell disposed on the first substrate together with the sensing unit, and configured to generate a power by receiving light; a wireless communication unit disposed at one side on the first substrate, and configured to transmit the information measured by the sensing unit to an external server; and a chemical cell disposed at another side on the first substrate, charged by receiving the power from the solar cell, and configured to supply the power to the sensing unit and the wireless communication unit, wherein the solar cell includes: a compound layer disposed on the second substrate, and configured to generate the power to be supplied to the sensing unit by receiving light; and a metallic electrode formed on the compound layer.

This disclosure relates to semiconductor devices and methods for fabricating semiconductor devices. Particularly, the disclosure relates to back-contact-only multijunction solar cells and the process flows for making such solar cells, including a wet etch process that removes semiconductor materials non-selectively without major differences in etch rates between heteroepitaxial III-V semiconductor layers.

A method of disordering a layer of an optoelectronic device including; growing a plurality of lower layers; introducing an isoelectronic surfactant; growing a layer; allowing the surfactant to desorb; and growing subsequent layers all performed at a low pressure of 25 torr.