The demand for on-chip multifunctional optoelectronic systems is increasing in the Internet-of-Things era. Spectral emission–detection overlap endows an InGaN/GaN quantum well diode (QWD) with an intriguing capability to detect and modulate light emitted by itself, which is of great interest when merging electronics and photonics together on a single chip for the development of advanced information systems. When biased and illuminated at approximately the same time, the InGaN/GaN QWD can achieve light emission and detection simultaneously. Herein, we experimentally demonstrate the simultaneous emission–detection phenomenon and analyze the irreversibility of spectral emission–detection overlap according to energy diagram theory, which may answer why the QWD can only detect and modulate higher-energy photons than those emitted by itself.
Wireless technologies can be used to track and observe freely moving animals. InGaN/GaN light-emitting diodes (LEDs) allow for underwater optical wireless communication due to the small water attenuation in the blue-green spectrum region. GaN-based quantum well diodes can also harvest and detect light. Here, we report a monolithic GaN optoelectronic system (MGOS) that integrates an energy harvester, LED and SiO2/TiO2 distributed Bragg reflector (DBR) into a single chip. The DBR serves as waterproof layer as well as optical filter. The waterproof MGOS can operate in boiling water and ice without external interconnect circuits. The units transform coded information from an external light source into electrical energy and directly activate the LEDs for illumination and relaying light information. We demonstrate that our MGOS chips, when attached to Carassius auratus fish freely swimming in a water tank, simultaneously conduct wireless energy harvesting and light communication. Our devices could be useful for tracking, observation and interacting with aquatic animals.
GaN-based devices have grown rapidly in recent decades, due to their important research value and application prospects. There is a desire to monolithically integrate different GaN devices into a single chip for the development of future optoelectronic systems with low power consumption. In addition to improved multifunctional performance, a miniature integrated system can result in a significant reduction in material costs, processing costs, and packaging costs. In view of such prospects, we propose monolithic, top-down approaches to build III-nitride transmitter, modulator, waveguide, beam splitter, receiver, and monitor as a single unit onto a conventional GaN-on-silicon wafer without involving regrowth or postgrowth doping. Data communication among these components is realized through light propagation, opening up horizons for GaN optoelectronic systems on a chip.
Optical fiber curvature sensors have been considered as a promising option for human motion detection due to its good toughness, bending flexibility and anti-electromagnetic interference. However, for wearable devices, the miniature configuration is preferred, and a high integration of the light emitter, receiver and guided fiber is essential to configure the miniaturized sensing system. Here, we present a miniaturized curvature sensing system by integrating a GaN-based optoelectronic chip with the plastical optical fiber (POF). The light emitter and detector are fabricated on a GaN-on-sapphire wafer to form a tiny chip sized at 2.5 $$\times$$ × 1.5 mm2. The on-chip photodetector (PD) effectively senses the reflected light intensity, extracting information on the fiber bending deformation. A compact curvature sensing system is demonstrated for finger motion detection with movement angles of 30–90° and frequencies of 0.4, 1, and 1.6 Hz. The results show that the monolithically integrated LED and PD chip can be combined with the POF with reliable operation. The demonstration of the monolithically integrated optoelectronic device suggests a promising potential technology for future wearable fiber optical sensor system.
Rare-earth nickelates-based high-entropy oxide (La 0.2 Pr 0.2 Nd 0.2 Sm 0.2 -Eu 0.2 )NiO 3 thin films (HEO-Ni) were deposited on (100)-, (110)-, and (111)oriented LaAlO 3 substrates via chemical solution deposition. All HEO-Ni films show epitaxial grain growth, and demonstrate first-order metal-to-insulator transition (MIT) with a sharp resistance change of over two orders of magnitude. Especially, the (110)-epitaxial HEO-Ni thin films, besides a transition temperature of 153 K, show an absolute sharpness of 0.33 K −1 and a resistance change of 2.5 × 10 4 . However, there are different lattice constant/strain and MTI characteristics for the differently oriented HEO-Ni thin films. Their electrical transport anisotropy may be attributed to the varied electron−phonon coupling and localization introduced by the different lattice constants, oxygen vacancies, and grain growth strains caused by the different crystal surfaces and interface energies. All of these results not only indicate the high quality of our derived films, but also suggest that the solution can be an effective alternative method to synthesize HEO thin films.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.