Bidirectional photocurrent in p–n heterojunction nanowires

Advanced Optical Materials

Kang

et al. 2022

Self Cite

The emerging photoelectrochemical‐type photodetector (PEC‐PD), because of its unique device architecture by using an aqueous electrolyte, is naturally applicable in the pursuit of underwater optical communication without sophisticated device packaging and assembling. Unfortunately, the traditional PEC detecting process typically involves a large electrochemical workstation with long cables and wire connections for photo signal acquisition, which hinders its applications in wireless optical communication. In this work, an AlGaN nanowire‐based self‐powered PEC‐PD is fabricated that uses seawater as an electrolyte, and then an optical communication system including the PEC‐PD and a portable electrochemical workstation as the signal receiver for data communication is built. Essentially, the self‐power PEC‐PD shows a high responsivity of −15.5 mA W–1, a fast response/recovery time of ≈100 ms, and high stability operation in the seawater electrolyte. Foremost, the optical communication system shows high accuracy in wireless transmission of ASCII code signals in a seawater environment. Such a demonstration offers a new device architecture for possible under‐seawater communication systems by leveraging the unique operation principle of photoelectrochemical devices in the future.

Section: Resultsmentioning

confidence: 99%

Section: Demonstration Of Photoelectrochemical-type Photodetectors Us...mentioning

confidence: 99%

Demonstration of Photoelectrochemical‐Type Photodetectors Using Seawater as Electrolyte for Portable and Wireless Optical Communication

Luo

Advanced Optical Materials

Kang

et al. 2022

Self Cite

“…Functional nanomaterials have been widely used in a variety of applications such as sensing [1,2], energy harvesting [3][4][5], and medical treatments [6] due to their unique physicochemical performance compared with conventional bulk counterparts. Current challenges in this field are the accurate assembly and rapid integration of these functional nanomaterials for various application requirements.…”

Section: Introductionmentioning

confidence: 99%

Controllable Melting and Flow of Ag in Self-Formed Amorphous Carbonaceous Shell for Nanointerconnection

Shi

et al. 2022

Micromachines

Nanointerconnection has been selected as a promising method in the post-Moore era to realize device miniaturization and integration. Even with many advances, the existing nanojoining methods still need further developments to meet the three-dimensional nanostructure construction requirements of the next-generation devices. Here, we proposed an efficient silver (Ag)-filled nanotube fabrication method and realized the controllable melting and ultrafine flow of the encapsulated silver at a subfemtogram (0.83 fg/s) level, which presents broad application prospects in the interconnection of materials in the nanometer or even subnanometer. We coated Ag nanowire with polyvinylpyrrolidone (PVP) to obtain core–shell nanostructures instead of the conventional well-established nanotube filling or direct synthesis technique, thus overcoming obstacles such as low filling rate, discontinuous metalcore, and limited filling length. Electromigration and thermal gradient force were figured out as the dominant forces for the controllable flow of molten silver. The conductive amorphous carbonaceous shell formed by pyrolyzing the insulative PVP layer was also verified by energy dispersive spectroscopy (EDS), which enabled the continued outflow of the internal Ag. Finally, a reconfigurable nanointerconnection experiment was implemented, which opens the way for interconnection error correction in the fabrication of nanoelectronic devices.

“…Intriguingly, the photoelectrochemical (PEC) devices emerge as promising candidates for self-powered photosensing while they are easy-to-fabricate and exhibit tunable photoresponse performance. [17][18][19][20] Specifically, Zhang et al employed different 2D semiconductors such as few-layer niobium carbide MXene and graphdiyne to build photoelectrochemical devices. [20][21][22] Most importantly, by virtue of their unique operation principle that the photon sensing process is based on the combination of physical and chemical processes, [23] they work completely different from conventional solid-state photodetectors.…”

Section: Introductionmentioning

confidence: 99%

“…Intriguingly, the photoelectrochemical (PEC) devices emerge as promising candidates for self‐powered photosensing while they are easy‐to‐fabricate and exhibit tunable photoresponse performance. [ 17–20 ] Specifically, Zhang et al. employed different 2D semiconductors such as few‐layer niobium carbide MXene and graphdiyne to build photoelectrochemical devices.…”

Section: Introductionmentioning

confidence: 99%

Photovoltage‐Competing Dynamics in Photoelectrochemical Devices: Achieving Self‐Powered Spectrally Distinctive Photodetection

Liu

Kang

et al. 2021

Adv Funct Materials

Self Cite

Multiple-band and spectrally distinctive photodetection play critical roles in building next-generation colorful imaging, spectroscopy, artificial vision, and optically controlled logic circuits of the future. Unfortunately, it remains challenging for conventional semiconductor photodetectors to distinguish different spectrum bands with photon energy above the bandgap of the material. Herein, for the first time, a photocurrent polarity-switchable photoelectrochemical device composed of group III-nitride semiconductors, demonstrating a positive photocurrent density of 10.54 µA cm −2 upon 254 nm illumination and a negative photocurrent density of −0.08 µA cm −2 under 365 nm illumination without external power supply, is constructed. Such bidirectional photocurrent behavior arises from the photovoltage-competing dynamics across two photoelectrodes. Importantly, a significant boost of the photocurrent and corresponding responsivity under 365 nm illumination can be achieved after decorating the counter electrode of n-type AlGaN nanowires with platinum (Pt) nanoparticles, which promote a more efficient redox reaction in the device. It is envisioned that the photocurrent polarity-switch behavior offers new routes to build multiple-band photodetection devices for complex light-induced sensing systems, covering a wide spectrum band from deep ultraviolet to infrared, by simply engineering the bandgaps of semiconductors.