Photovoltaic (PV) cell structures are disclosed. In one example embodiment, a PV cell includes an emitter layer, a base layer adjacent to the emitter layer, and a back surface field (BSF) layer adjacent to the base layer. The BSF layer includes a first layer, and a second layer adjacent to the first layer. The first layer includes a first material and the second layer includes a second material different than the first material.

A bonded semiconductor light-receiving device including an epitaxial layer to serve as a device-functional layer, and a support substrate made of a material different from that of the device-functional layer and bonded to the epitaxial layer via a bonding material layer. The device-functional layer has a bonding surface with an uneven pattern formed thereon.

Techniques for enhancing the absorption of photons in semiconductors with the use of microstructures are described. The microstructures, such as pillars and/or holes, effectively increase the effective absorption length resulting in a greater absorption of the photons. Using microstructures for absorption enhancement for silicon photodiodes and silicon avalanche photodiodes can result in bandwidths in excess of 10 Gb/s at photons with wavelengths of 850 nm, and with quantum efficiencies of approximately 90% or more.

A semiconductor structure includes a group IV substrate and a patterned group III-V device over the group IV substrate. A blanket dielectric layer is situated over the patterned group III-V device. Contact holes in the blanket dielectric layer are situated over the patterned group III-V device. A liner stack having at least one metal liner is situated in each contact hole. Filler metals are situated over each liner stack and fill the contact holes. The patterned group III-V device can be optically and/or electrically connected to group IV devices in the group IV substrate.

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.

A photosensitive sensor includes a pixel formed by a photosensitive region in a first semiconductor material, a read region in a second semiconductor material, and a transfer gate facing the parts of the first semiconductor material and the second semiconductor material located between the photosensitive region and the read region. The first semiconductor material and the second semiconductor material have different band gaps and are in contact with one another to form a heterojunction facing the transfer gate.

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.

A multijunction solar cell including interconnected first and second discrete semiconductor regions disposed adjacent and parallel to each other including first top solar subcell, second (and possibly third) lattice matched middle solar subcells; a graded interlayer adjacent to the last middle solar subcell; and a bottom solar subcell adjacent to said graded interlayer being lattice mismatched with respect to the last middle solar subcell; wherein an opening is provided from the bottom side of the semiconductor body to one or more of the solar subcells so as to allow a discrete electrical connector to be made extending in free space and to electrically connect contact pads on one or more of the solar subcells.

An ICIP comprises: a number N.sub.s of IC stages, wherein N.sub.s is configured to achieve a fundamental limit of the detectivity D.sub.peak* the ICIP within a range, and wherein each of the IC stages comprises: a hole barrier; an absorber coupled to the hole barrier and comprising a thickness d, wherein d is configured to achieve D.sub.peak* within the range; and an electron barrier coupled to the absorber. A method of manufacturing an ICIP comprises: determining a number N.sub.s of IC stages of the ICIP, wherein N.sub.s is configured to achieve a peak detectivity D.sub.peak* of the ICIP within a range; determining a thickness d of an absorber, wherein d is configured to achieve D.sub.peak* within the range; obtaining a substrate; forming an electron barrier on the substrate, the absorber having d on the electron barrier, and a hole barrier on the absorber; and repeating the forming N.sub.s times.

A method includes forming an assembly of layers including an InP cap layer on an InGaAs absorption region layer, wherein the InGaAs layer is on an n-InP layer, and wherein an underlying substrate layer underlies the n-InP layer. The method includes removing a portion of the InP cap and n-InP layer by dry etching.