The present invention provides a photodiode, which includes: a light absorption substrate, a first electrode portion, a second electrode portion, an antireflection layer, and a distributed Bragg reflection layer. The antireflection layer is arranged to receive light to get into the light absorption substrate. The antireflection layer is arranged to receive light to get into the light absorption substrate, and the distributed Bragg reflection layer is arranged to reflect light transmitting through the light absorption substrate to exit from the light absorption substrate back to the light absorption substrate, in order to enhance the photocurrent and the spectrum sensitivity of the photodiode.

Inhibition of movement of charges in a semiconductor element (100) formed by growing a group III-V compound semiconductor layer on a silicon substrate (110) is prevented. The semiconductor element (100) includes a silicon substrate (110), a first compound semiconductor layer (140), a second compound semiconductor layer (150), and an electrode (121). The first compound semiconductor layer (140) is formed on the silicon substrate (110). The second compound semiconductor layer (150) is stacked on the first compound semiconductor layer (140). The electrode (121) is disposed on the silicon substrate (110) and controls movement of charges between the silicon substrate (110) and the second compound semiconductor layer (150) via the first compound semiconductor layer (140).

A photodetector based on PtSe.sub.2 and a silicon nanopillar array includes a PMMA light-transmitting protective layer, a graphene transparent top electrode, a silicon nanopillar array structure coated with few-layer PtSe.sub.2, and metal electrodes of the graphene transparent top electrode and the silicon nanopillar array structure. A method for preparing the photodetector includes steps of: preparing graphene with a CVD method; preparing a silicon nanopillar array structure through dry etching; coating few-layer PtSe.sub.2 on surfaces of the silicon nano-pillar array structure through laser interference enhanced induction CVD; preparing graphene transparent top electrode; and magnetron-sputtering metal electrodes. The photodetector prepared by the present invention has a detection range from visible light to near-infrared wavebands. The silicon nanopillar array structure enhances light absorption of the detector, so that the detector has high sensitivity, simple structure and strong practicability.

A photodetector based on PtSe.sub.2 and a silicon nanopillar array includes a PMMA light-transmitting protective layer, a graphene transparent top electrode, a silicon nanopillar array structure coated with few-layer PtSe.sub.2, and metal electrodes of the graphene transparent top electrode and the silicon nanopillar array structure. A method for preparing the photodetector includes steps of: preparing graphene with a CVD method; preparing a silicon nanopillar array structure through dry etching; coating few-layer PtSe.sub.2 on surfaces of the silicon nano-pillar array structure through laser interference enhanced induction CVD; preparing graphene transparent top electrode; and magnetron-sputtering metal electrodes. The photodetector prepared by the present invention has a detection range from visible light to near-infrared wavebands. The silicon nanopillar array structure enhances light absorption of the detector, so that the detector has high sensitivity, simple structure and strong practicability.

According to the present disclosure, techniques related to manufacturing and applications of power photodiode structures and devices based on group-III metal nitride and gallium-based substrates are provided. More specifically, embodiments of the disclosure include techniques for fabricating photodiode devices comprising one or more of GaN, AIN, InN, InGaN, AlGaN, and AlInGaN, structures and devices. Such structures or devices can be used for a variety of applications including optoelectronic devices, photodiodes, power-over-fiber receivers, and others.

According to the present disclosure, techniques related to manufacturing and applications of power photodiode structures and devices based on group-III metal nitride and gallium-based substrates are provided. More specifically, embodiments of the disclosure include techniques for fabricating photodiode devices comprising one or more of GaN, AIN, InN, InGaN, AlGaN, and AlInGaN, structures and devices. Such structures or devices can be used for a variety of applications including optoelectronic devices, photodiodes, power-over-fiber receivers, and others.

According to the present disclosure, techniques related to manufacturing and applications of power photodiode structures and devices based on group-III metal nitride and gallium-based substrates are provided. More specifically, embodiments of the disclosure include techniques for fabricating photodiode devices comprising one or more of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, structures and devices. Such structures or devices can be used for a variety of applications including optoelectronic devices, photodiodes, power-over-fiber receivers, and others.

According to the present disclosure, techniques related to manufacturing and applications of power photodiode structures and devices based on group-III metal nitride and gallium-based substrates are provided. More specifically, embodiments of the disclosure include techniques for fabricating photodiode devices comprising one or more of GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, structures and devices. Such structures or devices can be used for a variety of applications including optoelectronic devices, photodiodes, power-over-fiber receivers, and others.

Embodiments disclosed herein facilitates the monitoring of direct ultraviolet B (UVB) radiation exposure by a person via a system having a sensor (such as Lanthanum doped lead zirconate titanate (PLZT) thin-film sensors or other ferroelectric-based sensors) sensitive to UVB radiation. The system beneficially provides current real-time dosage information associated with Vitamin D production by the person as well as real-time indication of safe exposure and/or harmful exposure to current UVB radiation conditions while also, in some embodiments, takes into consideration a person's age, skin type and sensitivity, body surface area exposed.

Embodiments disclosed herein facilitates the monitoring of direct ultraviolet B (UVB) radiation exposure by a person via a system having a sensor (such as Lanthanum doped lead zirconate titanate (PLZT) thin-film sensors or other ferroelectric-based sensors) sensitive to UVB radiation. The system beneficially provides current real-time dosage information associated with Vitamin D production by the person as well as real-time indication of safe exposure and/or harmful exposure to current UVB radiation conditions while also, in some embodiments, takes into consideration a person's age, skin type and sensitivity, body surface area exposed.