To improve an optical signal to electrical signal of a photodiode (PD) which is part of an integrated circuit, the PD can be modified to reduce noise and improve the gain bandwidth. In some aspects, the absorption region of the PD can utilize a non-rectangular geometry, for example, a clipped tapered geometry which can absorb the optical signal in more linearly than a rectangular geometry. In some aspects, the input optical signal can be split into two or more split optical signals, where each split optical signal is directed toward a different portion of the absorption region. The incident power of the optical signal transmitted to each respective portion of the absorption region can be reduced by dividing the incident power by the number of split optical signals thereby improving the gain and bandwidth saturation of each portion of the absorption region.

An example Geiger mode avalanche photodiode includes a first semiconductor alloy forming a compositionally graded gain region configured to form a conduction band having free electrons, a valence band having free holes, and a bandgap between the valence band and the conduction band that varies in size across the graded gain region; a second semiconductor alloy forming an absorber region; and a semiconductor substrate.

An avalanche photodiode detector is provided. The avalanche photodiode detector comprises an absorber region having an absorption layer for receiving incident photons and generating charged carriers; and a multiplier region having a multiplication layer; wherein the multiplier region is on a mesa structure separate from the absorber region and is coupled to the absorber region by a bridge for transferring charged carriers between the absorber region and multiplier region.

A photovoltaic or light detecting device is provided that includes a periodic array of dome or dome-like protrusions at the light impingement surface and a metal-less reflector/back electrode at the device back. The beneficial interaction between an appropriately designed top protrusion array and metal-less reflector/electrode back contact (R/EBC) serves (1) to refract the incoming light thereby providing photons with an advantageous larger momentum component parallel to the plane of the back (R/EBC) contact and (2) to provide optical impedance matching for the short wavelength incoming light. The metal-less reflector/back electrode operates as a back light reflector and counter electrode to the periodic array of dome or dome-like structures. A substrate supports the metal-less reflector/back electrode.

The disclosure provides a multi-junction solar cell structure and the manufacturing method thereof, comprising a first photovoltaic structure and a second photovoltaic structure; wherein at least one of the first photovoltaic structure and the second photovoltaic structure comprises a discontinuous photoelectric converting structure.

Disclosed are a solar cell and a method for manufacturing the same. The solar cell comprises asymmetric nanowires each of which has an angled sidewall, and thus incident light can be concentrated at a p-n junction portion by means of a total reflection phenomenon of light caused by the difference between the refractive indices of a semiconductor layer and a transparent electrode layer, and light absorption may increase due to an increase in the light travel distance, thus improving photoelectric efficiency. Further, the method for manufacturing the solar cell involves etching a substrate and integrally forming the substrate and a p-type semiconductor layer including the asymmetric nanowires each of which has the angled sidewalls, thereby enabling reduced manufacturing costs and simple and easy manufacture of the nanowires having the angled sidewalls.

Methods of fabricating solar cell emitter regions using silicon nano-particles and the resulting solar cells are described. In an example, a method of fabricating an emitter region of a solar cell includes forming a region of doped silicon nano-particles above a dielectric layer disposed above a surface of a substrate of the solar cell. A layer of silicon is formed on the region of doped silicon nano-particles. At least a portion of the layer of silicon is mixed with at least a portion of the region of doped silicon nano-particles to form a doped polycrystalline silicon layer disposed on the dielectric layer.

Disclosed are devices for optical sensing and manufacturing method thereof. In one embodiment, a device for optical sensing includes a substrate, a photodetector and a reflector. The photodetector is disposed in the substrate. The reflector is disposed in the substrate and spaced apart from the photodetector, wherein the reflector has a reflective surface inclined relative to the photodetector that reflects light transmitted thereto to the photodetector.

A semiconductor photodetector element includes a semiconductor substrate having a first conductivity type; a columnar structure formed on a first surface of the semiconductor substrate, the columnar structure being composed of a semiconductor of the first conductivity type; a light absorption layer formed so as to surround the columnar structure; and a semiconductor layer formed so as to surround the light absorption layer.

The invention provides hybrid photovoltaic-piezoelectric energy harvesting devices in the form of flexible filaments. The devices harvest energy from ambient light, and also from environmental motions and vibrations. They are particularly suitable for incorporation into fabrics and clothing.