the radiation emitted by the room-temperature object is mainly in the LWIR region, with the peak wavelength of about 10 µm. [1] Because of these two properties, photodetectors operating in the LWIR range are of significant importance for the heat-seeking technologies, such as all-weather surveillance, night vision, and missile guidance. To detect such lowenergy radiation by photon detectors, commonly used photosensitive materials are narrow-bandgap semiconductors (e.g., HgCdTe) and quantum wells (e.g., GaAs/ InGaAs). [2,3] For these photodetectors, the dark current at room temperature usually is large, and thus a cryogenic cooling unit is indispensable, which certainly increases the size and weight of photon detectors. Therefore, to miniaturize the volume and weight of LWIR detectors, the development of high-performance uncooled photodetectors is vital. Thermal detectors are well known for their ultra-broadband spectral response from UV to far-infrared and even to terahertz at room temperature. The excellent ability of terahertz radiation (0.1-1 mm) to penetrate through nonconducting materials renders it particularly attractive for applications in tomographic inspection. [4,5] Thermal detectors are based on the measurement of temperature-dependent properties, such as the resistance for bolometers, the temperature-difference-driven voltage for photothermoelectric (PTE) detectors, and the spontaneous polarization for pyroelectric (PE) detectors. The photoresponse in PE detectors depends on the variation of the spontaneous polarization vector with temperature; therefore, an external chopper is needed when measuring the power of continuous-wave (CW) radiation. For bolometers, an external bias is required, which introduces the extra 1/f noise. The typical temperature-sensitive materials in commercial bolometers are vanadium oxide (VO x ) or amorphous silicon. The main advantage of VO x lies in that its temperature coefficient of resistance is high (≈4% K −1 ) while the resistivity remains low, which is beneficial to reduce the noise level. [6] Detailed comparisons among different kinds of photodetectors are listed in Table 1.PTE detectors are based on the photothermal conversion and thermoelectric effect. As schematically shown in Figure 1, after absorbing the photons on one side of PTE detector, a temperature difference (ΔT) is built up, which drives the directed diffusion of charge carriers from the hot end to the cold end, establishing an electric potential difference (ΔU). This process High-performance uncooled photodetectors operating in the long-wavelength infrared and terahertz regimes are highly demanded in the military and civilian fields. Photothermoelectric (PTE) detectors, which combine photothermal and thermoelectric conversion processes, can realize ultra-broadband photodetection without the requirement of a cooling unit and external bias. In the last few decades, the responsivity and speed of PTE-based photodetectors have made impressive progress with the discovery of novel thermoelectric materials and ...

The self-powered and ultra-broadband photodetectors based on photothermoelectric (PTE) effect are promising for diverse applications such as sensing, environmental monitoring, night vision and astronomy. The sensitivity of PTE photodetectors is determined by the Seebeck coefficient and the rising temperature under illumination. Previous PTE photodetectors mostly rely on traditional thermoelectric materials with Seebeck coefficients in the range of 100 μV K−1, and array structures with multiple units are usually employed to enhance the photodetection performance. Herein, we demonstrate a reduced SrTiO3 (r-STO) based PTE photodetector with sensitivity up to 1.2 V W−1 and broadband spectral response from 325 nm to 10.67 μm. The high performance of r-STO PTE photodetector is attributed to its intrinsic high Seebeck coefficient and phonon-enhanced photoresponse in the long wavelength infrared region. Our results open up a new avenue towards searching for novel PTE materials beyond traditional thermoelectric materials for low-cost and high-performance photodetector at room temperature.

Phosphorus (P) is an essential nutrient for all organisms, thus playing unique and critical roles at the food-energy-water nexus. Most P utilized by human activities eventually converges into various solid biowastes, such as crop biomass, animal manures, and sewage sludges. Therefore, integration of efficient P recovery practices into solid biowaste management will not only significantly reduce the dependence on limited geological P resources but also reduce P runoff and related water contamination issues associated with traditional waste management strategies. This study reviews the applications of (hydro)thermal techniques for the treatment of solid biowastes, which can greatly facilitate P recovery in addition to waste volume reduction, decontamination, and energy recovery. Research showed that P speciation (including molecular moiety, complexation state, and mineralogy) can experience significant changes during (hydro)thermal treatments, and are impacted by treatment techniques and conditions. Changes in P speciation and overall properties of the products can alter the mobility and bioavailability of P, and subsequent P reclamation and recycling efficiency of the treatment products. This review summarizes recent progresses in this direction, identifies the challenges and knowledge gaps, and provides a foundation for future research efforts targeting at sustainable management of nutrient-rich biowastes.

No abstract

No abstract

Interface charge transfer and electron–phonon coupling have been suggested to play a crucial role in the recently discovered high-temperature superconductivity of single unit-cell FeSe films on SrTiO3. However, their origin remains elusive. Here, using ultraviolet photoemission spectroscopy and element-sensitive X-ray photoemission spectroscopy, we identify the strengthened Ti–O bond that contributes to the interface enhanced electron–phonon coupling and unveil the band bending at the FeSe/SrTiO3 interface that leads to the charge transfer from SrTiO3 to FeSe films. We also observe band renormalization that accompanies the onset of superconductivity. Our results not only provide valuable insights into the mechanism of the interface-enhanced superconductivity, but also point out a promising route toward designing novel superconductors in heterostructures with band bending-induced charge transfer and interfacial enhanced electron–phonon coupling.

No abstract

Simultaneous enhancement in the power factor and thermoelectric performance of copper sulfide is realized by introducing In2S3, which will be beneficial to the practical application.