Embodiments of the invention generally relate to photovoltaic devices. In one embodiment, a method for forming a gallium arsenide based photovoltaic device includes providing a semiconductor structure, the structure including an absorber layer comprising gallium arsenide. A bypass function is provided in a p-n junction of the semiconductor structure, where under reverse-bias conditions the p-n junction breaks down in a controlled manner by a Zener breakdown effect.

An avalanche photodiode (APD) structure, comprising an absorption layer comprising InGaAs, InGaAlAs, InGaAsP, or an InGaAs/GaAsSb type-II superlattice, an avalanche layer comprising AlGaAsSb, and a transition portion disposed between the absorption layer and the avalanche layer is disclosed. The transition portion comprises a first grading layer of InAlGaAs or InGaAsP and a first field control layer disposed between the first grading layer and the avalanche layer. The first field control layer has a bandgap between the bandgap of the absorption layer and the bandgap of the avalanche layer. In an alternative embodiment, an avalanche photodiode (APD) structure, comprising an absorption layer comprising GaAsSb, an avalanche layer comprising AlGaAsSb, and a transition portion disposed between the absorption layer and the avalanche layer. The transition portion comprises a first grading layer and one or more field control layers having a bandgap between the bandgaps of the absorption layer and the avalanche layer.

A light reception device of the present invention includes a first i-type cladding region, an n-type waveguide core having a predetermined width, and a second i-type cladding region in contact with a side surface of the n-type waveguide core on a substrate, includes a p-type absorption layer, a p-type diffusion barrier layer, a p-type contact layer, and a p-type electrode formed in an upper part above a region including a part of the n-type waveguide core, with an i-type insertion layer interposed between the upper part and the region, and includes an n-type electrode on an upper surface of another part of the n-type waveguide core.

Techniques for realizing compound semiconductor (CS) optoelectronic devices on silicon (Si) substrates for mobile applications are disclosed. The integration platform is based on heteroepitaxy of CS materials and device structures on Si by direct heteroepitaxy on planar Si substrates or by selective area heteroepitaxy on dielectric patterned Si substrates. Following deposition of the CS device structures, device fabrication steps can be carried out using Si complimentary metal-oxide semiconductor (CMOS) fabrication techniques to enable large-volume manufacturing. The integration platform can enable manufacturing of optoelectronic devices including photodetector arrays for image sensors and vertical cavity surface emitting laser arrays. Such devices can be used in various applications including light detection and ranging (LIDAR) systems for mobile devices such as smart phones and tablets, and for other perception applications such as industrial vision, artificial intelligence (AI), augmented reality (AR) and virtual reality (VR).

Techniques for realizing compound semiconductor (CS) optoelectronic devices on silicon (Si) substrates are disclosed. The integration platform is based on heteroepitaxy of CS materials and device structures on Si by direct heteroepitaxy on planar Si substrates or by selective area heteroepitaxy on dielectric patterned Si substrates. Following deposition of the CS device structures, device fabrication steps can be carried out using Si complimentary metal-oxide semiconductor (CMOS) fabrication techniques to enable large-volume manufacturing. The integration platform can enable manufacturing of optoelectronic devices including photodetector arrays for image sensors and vertical cavity surface emitting laser arrays. Such devices can be used in various applications including light detection and ranging (LIDAR) systems for automotive and robotic vehicles as well as mobile devices such as smart phones and tablets, and for other perception applications such as industrial vision, artificial intelligence (AI), augmented reality (AR) and virtual reality (VR).

A first n-type contact layer, a second n-type contact layer, a multiplication layer, an electric field control layer, a light absorbing layer, and a p-type contact layer are layered in this order on a substrate. The second n-type contact layer is formed between the first n-type contact layer and the light absorbing layer, is made to have an area smaller than that of the light absorbing layer in a plan view, and is disposed inside the light absorbing layer in a plan view.

There is provided an element structure of an avalanche photodiode that can operate in a high gain state while having high reliability and low noise property. There is produced an avalanche photodiode including at least a multiplication layer and a light absorbing layer between first and second semiconductor contact layers, in which an area of the first semiconductor contact layer is at least smaller than an area of the multiplication layer, the avalanche photodiode having an electric field relaxation layer configured to be depleted at an operating voltage between the first semiconductor contact layer and the multiplication layer.

A compound-semiconductor photovoltaic cell includes a first photoelectric conversion cell made of a first compound-semiconductor material which lattice matches with GaAs or Ge; a first tunnel junction layer arranged on a deep side farther than the first photoelectric conversion cell in a light incident direction, and including a first p-type (Al.sub.x1Ga.sub.1-x1).sub.y1In.sub.1-y1As (0≤x1<1, 0<y1≤1) layer and a first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P (0≤x2<1, 0<y2<1) layer; and a second photoelectric conversion cell arranged on a deep side farther than the first tunnel junction layer in the light incident direction, and made of a second compound-semiconductor material which is a GaAs-based semiconductor material. The first photoelectric conversion cell and the second photoelectric conversion cell are joined via the first tunnel junction layer, and a lattice constant of the first n-type (Al.sub.x2Ga.sub.1-x2).sub.y2In.sub.1-y2P layer is greater than a lattice constant of the first photoelectric conversion cell.

Techniques for realizing compound semiconductor (CS) optoelectronic devices on silicon (Si) substrates are disclosed. The integration platform is based on heteroepitaxy of CS materials and device structures on Si by direct heteroepitaxy on planar Si substrates or by selective area heteroepitaxy on dielectric patterned Si substrates. Following deposition of the CS device structures, device fabrication steps can be carried out using Si complimentary metal-oxide semiconductor (CMOS) fabrication techniques to enable large-volume manufacturing. The integration platform can enable manufacturing of optoelectronic module devices including photodetector arrays for image sensors and vertical cavity surface emitting laser arrays. Such module devices can be used in various applications including light detection and ranging (LIDAR) systems for automotive and robotic vehicles as well as mobile devices such as smart phones and tablets, and for other perception applications such as industrial vision, artificial intelligence (AI), augmented reality (AR) and virtual reality (VR).

The present disclosure provides an integrated infrared circular polarization detector with a high extinction ratio and a design method thereof. The detector structurally includes a metal reflective layer, a bottom electrode layer, a quantum well layer, a top electrode layer, and a two-dimensional chiral metamaterial layer. Under circularly polarized light with the selected handedness, surface plasmon polariton waves are generated at the interface between the two-dimensional chiral metamaterial layer and the semiconductor, and has a main electric field component aligned with the absorption direction of the quantum wells, thereby enhancing the absorption of the quantum wells. Under circularly polarized light with the opposite handedness, since most of the optical power is reflected, surface plasmon polariton waves cannot be effectively excited, and the absorption of the quantum wells is extremely low, thus realizing the capability of infrared circular polarization detection with a high extinction ratio.