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

Abstract

Photoelectrochemical‐type visible‐blind ultraviolet photodetectors (PEC VBUV PDs) have gained ever‐growing attention due to their simple fabrication processes, uncomplicated packaging technology, and high sensitivity. However, it is still challenging to achieve high‐performance PEC VBUV PDs based on a single material with good spectral selectivity. Here, it is demonstrated that individual ultrathin indium oxide (In2O3) nanosheets (NSs) are suitable for designing high‐performance PEC VBUV PDs with high responsivity and UV/visible rejection ratio for the first time. In2O3 NSs PEC PDs show excellent UV photodetection capability with an ultrahigh photoresponsivity of 172.36 mA W−1 and a high specific detectivity of 4.43 × 1011 Jones under 254 nm irradiation, which originates from the smaller charge transfer resistance (Rct) at the In2O3 NSs/electrolyte interface. The light absorption of In2O3 NSs takes a blueshift due to the quantum confinement effect, granting good spectral selectivity for visible‐blind detection. The UV/visible rejection ratio of In2O3 NSs PEC PDs is 1567, which is 30 times higher than that of In2O3 nanoparticles (NPs) and exceeds all recently reported PEC VBUV PDs. Moreover, In2O3 NSs PEC PDs show good stability and good underwater imaging capability. The results verify that ultrathin In2O3 NSs have potential in underwater optoelectronic devices.

A two-dimensional Te/ReS2 van der Waals heterostructure photodetector with high photoresponsivity and fast photoresponse

“…The decrease of all the above metrics with increasing light intensity is probably due to the existence of trap states at the interface between Te/ReS 2 and the substrate, which is a common phenomenon in vdWH based photodetectors. 38,44,45 Under relatively low intensity conditions, the interface states will be occupied by the holes separated from the photogenerated electron-hole pairs. As the incident light intensity increases, an increasing number of electron-hole pairs is generated, indicating the diminishing of hole-trap states at the surface.…”

Highly Sensitive and Stable Visible-Light Self-Power Photodetectors Based on Solution-Processed Bi4O5I2

“…Promisingly, the recently reported two-electrode-based PEC-type photodetectors, only consisting of the working and counter electrodes, , exhibited a great potential in practical applications. Until now, the highest responsivity for the PEC-type photodetectors has reached up to hundreds of mA/W and detectivity has been achieved in the order of 10 10 Jones. ,− Based on the previous reports, it can be deduced that the optoelectronic material is one of the critical factors for the performance of photodetectors. Recently, pnictogen-based materials, ,, such as black phosphorus and bismuth, owing to their unique properties and excellent optoelectronic properties, have been gradually applied for the construction of PEC-type photodetectors and have exhibited promising photodetection performance.…”

High-Performance Nanoplasmonic Enhanced Indium Oxide—UV Photodetectors

“…On the other hand, indium oxide is a desirable material for developing smart, flexible, and wearable optoelectronics and multifunctional sensors in the field of environmental indicators [6], owing to its wide band gap (with reported values ranging from 2.7 to 3.7 eV) [7], optical transparency, thermal and chemical resistance, flexibility and stretchability, ease of manufacturing and low fabrication cost. Hence, UV photodetectors (PDs) based on In 2 O 3 nanostructures, such as nanowires [8][9][10], quantum dots [11], nanosheets [12], and nanoparticles [13], have been explored, which demonstrates that In 2 O 3 is a candidate for developing UV PDs. However, there are neither reports on the UV photodetector based on In 2 O 3 thin films, nor studies on PD performance comparison at different temperatures.…”