Heterostructures containing one or more sheets of positive charge, or alternately stacked AlGaN barriers and AlGaN wells with specified thickness are provided. Also provided are multiple quantum well structures and p-type contacts. The heterostructures, the multiple quantum well structures and the p-type contacts can be used in light emitting devices and photodetectors.

Methods for forming interdigitated back contact solar cells from III-V materials are provided. According to an aspect of the invention, a method includes depositing a patterned Zn layer to cover first areas of an n-type emitter region, wherein the emitter region comprises a III-V material, and forming a passivated back contact region by counter-doping the first areas of the emitter region by diffusing Zn from the patterned Zn layer into the first areas of the emitter region, such that the first areas of the emitter region become p-type.

A semiconductor stacked body includes: a first semiconductor layer containing a group III-V compound semiconductor and being a layer whose conductivity type is a first conductivity type; a quantum-well light-receiving layer containing a group III-V compound semiconductor; a second semiconductor layer containing a group III-V compound semiconductor; and a third semiconductor layer containing a group III-V compound semiconductor and being a layer whose conductivity type is a second conductivity type. The first semiconductor layer, the quantum-well light-receiving layer, the second semiconductor layer, and the third semiconductor layer are stacked in this order. The concentration of an impurity that generates a carrier of the second conductivity type is 110.sup.14 cm.sup.3 or more and 110.sup.17 cm.sup.3 or less in the second semiconductor layer.

Disclosed is a method of manufacturing a compound semiconductor solar cell according to an embodiment of the invention. The method of manufacturing the compound semiconductor solar cell according to the embodiment of the invention includes forming a plurality of compound semiconductor layers of at least two elements and including a base layer and an emitter layer, the base layer including a first conductivity type dopant to have a first conductivity type and the emitter layer including a second conductivity type dopant to have a second conductivity type. The forming of the plurality of compound semiconductor layers includes at least one of a process-temperature change period and a growth-rate change period.

A semiconductor laminate includes a substrate formed of a group III-V compound semiconductor and a quantum well structure disposed on the substrate. The quantum well structure includes a second element layer formed of a group III-V compound semiconductor and containing Sb and a first element layer formed of a group III-V compound semiconductor and disposed in contact with the second element layer. In the first element layer, the thickness of a region in which the content of Sb decreases in a direction away from the substrate from 80% of the maximum content of Sb in the second element layer to 6% of the maximum content is from 0.5 nm to 3.0 nm inclusive.

A photodiode (PD) device that monolithically integrates a PD element with a waveguide element is disclosed. The PD device includes a conducting layer with a first region and a second region next to the first region, where the PD element exists in the first region, while, the waveguide element exists in the second region and optically couples with the PD element. The waveguide element includes a core layer and a cladding layer on the conducting layer, which forms an optical confinement structure. The PD element includes an absorption layer on the conducting layer and a p-type cladding layer on the absorption layer, which form another optical confinement structure. The absorption layer has a length at least 12 m measured from the interface against the core layer.

Provided is an optical detection device including a first ohmic contact layer of a first conductivity type, a second ohmic contact layer of a second conductivity type, and first and second mesa structures stacked between the first and second ohmic contact layers. The first mesa structure includes an electric field buffer layer; and a diffusion layer formed in the electric field buffer layer. The second mesa structure includes a light absorbing layer and a grading layer on the light absorbing layer.

A solar battery includes a first electrode, a second electrode, a solar cell, an insulating layer and a gate electrode. The solar cell includes a semiconductor structure, a carbon nanotube and a transparent conductive film. The semiconductor structure includes a P-type semiconductor layer and an N-type semiconductor layer and defines a first surface and a second surface. The carbon nanotube is located on the first surface of the semiconductor. The transparent conductive film is located on the second surface of the semiconductor. The transparent conductive film is formed on the second surface by a depositing method or a coating method.

An infrared detecting semiconductor device comprises: an optical absorbing layer of type-II disposed between first conductivity-type and second conductivity-type semiconductor layers; and an optical filtering film of n-type InGaAs having an n-type dopant concentration larger than 810.sup.17 cm.sup.3. The optical filtering film includes first to third semiconductor regions, which are sequentially arranged in a direction of a first axis on the optical filtering film. The first semiconductor region has an n-type dopant concentration of 2.010.sup.19 cm.sup.3 or more. The third semiconductor region has a n-type concentration of 3.010.sup.18 cm.sup.3 or less. The second semiconductor region has an n-type dopant profile monotonically changing from a first dopant concentration at a boundary between the first and second semiconductor regions to a second dopant concentration at a boundary between the second and third semiconductor regions. The first dopant concentration is greater than the second dopant concentration.

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).