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

Abstract

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.

Progress on photovoltaic AlGaN photodiodes for solar-blind ultraviolet photodetection

“…Photoelectrochemical cells used for solar-blind photodetection are very special because they are composed of electrocatalytic chemistry and solar-blind photodetection, which gives the PCE-SBPDs self-powered characteristics. The specific configuration of PCE-SBPDs determines that they can play key roles in some specific fields, such as in-water communication, which is also reported in previous papers [186] . In practice, the compatibility between device configurations, fabrication processes, and operation conditions should be taken into consideration during the fabrication of AlGaN SBPDs.…”

Ultrathin In2O3 Nanosheets toward High Responsivity and Rejection Ratio Visible‐Blind UV Photodetection

“…Therefore, we will focus on the performance of ultrathin In reported ultrathin nanomaterial-based aqueous-type PEC UV PDs [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49] and are comparable with the record-high performance of recently reported PEC UV PDs, [17] as shown in Table S9, Supporting Information. The ultrahigh UV detection capability and the operation in weak alkaline electrolyte indicate that ultrathin In 2 O 3 NSs hold great prospects for underwater UV communication [12] (more detailed comparison in Table S6, Supporting Information). We will focus on investigating optoelectronic properties of In 2 O 3 NSs PEC PDs using seawater as the electrolyte in the future.…”

“…[1][2][3][4][5][6][7] Although conventional solid-state VBUV PDs have been widely investigated based on various wide-bandgap nanomaterials, [8][9][10] photoelectrochemical-type (PEC) VBUV PDs have attracted ever-growing attention due to their simple fabrication process, low-cost, high sensitivity, and potential applications in underwater optical communication. [11,12] Various wide-bandgap materials with different nanostructures have been designed for PEC VBUV PDs, [13][14][15][16] but single material-based PEC PDs usually show relatively poor photoresponse. [15,16] Some strategies have been developed for optimizing the performance of PEC VBUV PDs, such as coating heavy metal nanoparticles [17,18] and building heterojunctions, [19,20] and they inevitably increase complexity and cost.…”

Ordered GaN Nanorod Arrays for Self-Powered Photoelectrochemical Ultraviolet Photodetectors

“…Meanwhile, the built-in electric field generated by the SCR is beneficial for separating photogenerated carriers. Concretely, upon UV exposure, the photogenerated electrons readily jump from the valence band to the conduction band, flow to the working electrode under the action of the built-in electric field, and then are transported to the platinum counter electrode for the reduction reaction , 4H + + 4e – = 2H 2 , whereas the photoexcited holes in the valence band of GaN move to the electrolyte and participate in the oxidation reaction 2H 2 O + 4h + = O 2 + 4H + . Ultimately, conversion of the optical signals to electrical signals is monitored by an electrochemical workstation.…”