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In this work, we fabricate a semitransparent BiVO 4 photoanode via the synergistic effect of indium (In) doping and anoxic annealing. An optimized photocurrent density of 3.6 mA cm −2 at 2 V versus reversible hydrogen electrode is obtained in a sacrificial free electrolyte system (AM 1.5G 100 mW cm −2 ). Indoping increases the difficulty to form bonds between Bi atoms and O atoms in the crystal bulk. Thus, quasi-oxygen vacancies in the bulk of the BiVO 4 crystal can be induced under anoxic annealing to increase the mobility, lifetime, and concentration of the photogenerated carriers. On the other hand, anoxic annealing can inhibit the conversion rate of the BiOI nanosheet arrays to BiVO 4 to form a nanonet structure with a large surface reaction area. Therefore, through a simple In-doping and controlled anoxic annealing process, the photogenerated carriers and the nanomorphology of BiVO 4 photoanode are synergistically optimized.

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The application fields of infrared photodetectors are quite extensive. Compared with traditional infrared photodetection materials such as IV and III–V semiconductors, newly emerging low‐dimensional materials and quantum materials (e.g., 2D materials and quantum wells) have many advantages in different aspects, such as wide spectral range, low dark current, room temperature operation, and high processing compatibility. However, the performance of photodetectors based on low‐dimensional materials is limited by the ultra small thicknesses, polarization selectivity, and the poor absorption efficiency. Therefore, improving the performance of infrared photodetectors based on low‐dimensional materials has been a focus research task in recent years. The integration of photonic structures can improve the performance of infrared photodetectors, such as enhancing absorption efficiency, reducing the volume of active materials, and increasing polarization selectivity. Herein, different kinds of photonic structure integrated infrared photodetectors, roughly divided into two categories, namely, dielectric photonic structure integrated ones and metallic photonic structure integrated ones, are reviewed. The active materials include 2D materials, quantum wells, quantum dots, and carbon nanotubes.

GaN-based quantum well infrared detectors can make up for the weakness of GaAs-based quantum well infrared detectors for short-wave infrared detection. In this work, GaN/AlN (1.8 nm/1.8 nm) multi-quantum wells have been epitaxially grown on sapphire substrate using MBE technology. Meanwhile, based on this device structure, the band positions and carrier distributions of a single quantum well are also calculated. At room temperature, the optical response of the device is 58.6 μA/W with a bias voltage of 0.5 V, and the linearity between the optical response and the laser power is R2 = 0.99931. This excellent detection performance can promote the research progress of GaN-based quantum well infrared detectors in the short-wave infrared field.