Large-size 2D black phosphorus (BP) nanosheets have been successfully synthesized by a facile liquid exfoliation method. The as-prepared BP nanosheets are used to fabricate electrodes for a self-powered photodetector and exhibit preferable photoresponse activity as well as environmental robustness. Photoelectrochemical (PEC) tests demonstrate that the current density of BP nanosheets can reach up to 265 nA cm −2 under light irradiation, while the dark current densities fluctuate near 1 nA cm −2 in 0.1 M KOH. UV-vis and Raman spectra are carried out and confirm the inherent optical and physical properties of BP nanosheets. In addition, the cycle stability measurement exhibits no detectable distinction after processing 50 and 100 cycles, while an excellent on/off behavior is still preserved even after one month. Furthermore, the PEC performance of BP nanosheets-based photodetector is evaluated in various KOH concentrations, which demonstrates that the as-prepared BP nanosheets may have a great potential application in self-powered photodetector. It is anticipated that the present work can provide fundamental acknowledgement of the performance of a PEC-type BP nanosheets-based photodetector, offering extendable availabilities for 2D BPbased heterostructures to construct high-performance PEC devices.

Self‐powered photodetectors are considered as a new type of photodetectors enabling self‐powered photodetection without external power. The excellent photoresponsivity, fast photoresponse rate, low dark current, and large light on/off ratio of these photodetectors have attracted wide interest among scholars. 2D materials are widely used in self‐powered photodetectors due to their excellent optical and electrical properties, unique 2D structures, and their capabilities to exhibit excellent photodetection performance. According to the self‐driving mechanism of 2D material‐based self‐powered photodetectors, they are divided into three categories: p–n junction photodetectors, Schottky junction photodetectors, and photoelectrochemical photodetectors. From these three perspectives, the research progress of 2D material‐based self‐powered photodetectors is summarized in detail here. Research reports indicate that 2D material‐based self‐powered photodetectors have excellent self‐powered photoresponse behavior, good light on/off characteristics, and wideband spectral response ranges. The excellent photoresponse performance of 2D material‐based self‐powered photodetectors facilitates their potential applications in the field of optoelectronic devices. In particular, self‐powered photodetectors have great potential as novel emerging self‐driven optoelectronic devices. Finally, directions for the further development of 2D material‐based self‐powered photodetectors are anticipated.

The band gap of few‐layered 2D material is one of the significant issues for the application of practical devices. Due to the outstanding electrical transport property and excellent photoresponse, 2D InSe has recently attracted rising attention. Herein, few‐layered InSe nanosheets with direct band gap are delivered by a facile liquid‐phase exfoliation approach. We have synthesized a photoelectrochemical (PEC)‐type few‐layered InSe photodetector that exhibits high photocurrent density, responsivity, and stable cycling ability in KOH solution under the irradiation of sunlight. The detective ability of such PEC InSe photodetector can be conveniently tuned by varying the concentration of KOH and applied potential suggesting that the present device can be a fitting candidate as an excellent photodetector. Moreover, extendable optimization of the photodetection performance on InSe nanosheets would further enhance the potential of the prepared InSe in other PEC‐type devices such as dye‐sensitized solar cells, water splitting systems, and solar tracking equipment.

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PbSe/CdSe core/shell quantum dots (QDs) were prepared and investigated as thick films using temperature-dependent photoluminescence. In addition to increased photostability, the CdSe shell leads to a four-fold increase of the activation energy for nonradiative exciton decay for the core/shell QDs compared to that for the bare PbSe QDs. The onset for exponential decay of luminescence is ∼240 K in the core/shell samples. From further analysis of the temperature-dependent photoluminescence shift and emission line width, we find that the cation exchange reaction broadens the QD size distribution and increases the temperature-independent state broadening. However, the temperature-dependent contribution to the line shape of the core/shell QDs is similar to that in the cores.

Two dimensional Bi nanosheets have been employed to fabricate electrodes for broadband photo-detection. A series of characterization techniques including scanning electron microscopy and high-resolution transmission electron microscopy have verified that Bi nanosheets with intact lamellar structure have been obtained after facile liquid phase exfoliation. In the meanwhile, UV-vis and Raman spectra are also carried out and the inherent optical and physical properties of Bi nanosheets are confirmed. Inherited from the topological characteristics of Bi bulk counterpart, the resultant Bi nanosheet-based photo-detector exhibits preferable photo-response activity as well as environmental robustness. We then evaluate the photo-electrochemical (PEC) performance of the photodetector in 1 M NaOH and 0.5 M NaSO electrolytes, and demonstrated that the as-prepared Bi nanosheets may possess a great potential as PEC-type photo-detector. Additional PEC measurements show that the current density of Bi nanosheets can reach up to 830 nA cm, while an enhanced responsivity (1.8 μA W) had been achieved. We anticipate that this contribution can provide feasibility towards the construction of high-performance elemental Bi nanosheets-based optoelectronic devices in the future.

We present the calibration strategy for the 20 kton liquid scintillator central detector of the Jiangmen Underground Neutrino Observatory (JUNO). By utilizing a comprehensive multiple-source and multiple-positional calibration program, in combination with a novel dual calorimetry technique exploiting two independent photosensors and readout systems, we demonstrate that the JUNO central detector can achieve a better than 1% energy linearity and a 3% effective energy resolution, required by the neutrino mass ordering determination.

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