Blackbody-sensitive room-temperature infrared detection is a notable development direction for future low-dimensional infrared photodetectors. However, because of the limitations of responsivity and spectral response range for low-dimensional narrow bandgap semiconductors, few low-dimensional infrared photodetectors exhibit blackbody sensitivity. Here, highly crystalline tellurium (Te) nanowires and two-dimensional nanosheets were synthesized by using chemical vapor deposition. The low-dimensional Te shows high hole mobility and broadband detection. The blackbody-sensitive infrared detection of Te devices was demonstrated. A high responsivity of 6650 A W⁻¹ (at 1550-nm laser) and the blackbody responsivity of 5.19 A W⁻¹ were achieved. High-resolution imaging based on Te photodetectors was successfully obtained. All the results suggest that the chemical vapor deposition–grown low-dimensional Te is one of the competitive candidates for sensitive focal-plane-array infrared photodetectors at room temperature.

Iron (Fe)-doped (0 to 4%) TiO₂ nano-crystalline (nc) films with the grain size of about 25 nm have been deposited on n-type Si (100) substrates by a facile nonhydrolytic sol–gel processing. X-ray diffraction measurements prove that the films are polycrystalline and present the pure anatase phase. X-ray photoelectron spectroscopy spectra indicate that the chemical valent state of Fe element is +3 and the Fe³⁺ ions replace the Ti⁴⁺ sites. The Fe dopant effects on the surface morphology, microstructure, and dielectric functions of the nc-Fe/TiO₂ films have been studied by atomic force microscope, ultraviolet Raman scattering and spectroscopic ellipsometry. With increasing Fe composition, the intensity of Raman-active mode B_1g increases, while that of the A_1g phonon mode decreases. The dielectric functions have been uniquely extracted by fitting ellipsometric spectra with the Adachi's dielectric function model and a four-phase layered model. It is found that the real part of dielectric functions in the transparent region and the optical band gap slightly decrease with the Fe composition due to the introduction of acceptor level Fet_2g. Finally, the composition and temperature dependence of the surface and lattice defects in the Fe/TiO₂ films have been investigated by photoluminescence spectra in detail. At room temperature, the emission intensities decrease with increasing Fe compositions since the Fe incorporation could prolong the radiative lifetime and/or shorten the non-radiative lifetime. By analyzing the low temperature photoluminescence spectra, the intensities and positions of five emission peaks and shoulder structure can be unambiguously assigned. The phenomena could be reasonably explained by the physical mechanisms such as oxygen vacancies, localized excitons, self-trapped excitons, and indirect transitions, which are strongly related to the electronic band structure perturbed by the Fe doping.

Copper ferrites are emerging transition metal oxides that have potential applications in energy storage devices. However, it still lacks in-depth designing of copper ferrites based anode architectures with enhanced electroactivity for lithium-ion batteries. Here, we report a facile synthesis technology of copper ferrites anchored on reduced graphene oxide (CuFeO₂@rGO and Cu/CuFe₂O₄@rGO) as the high-performance electrodes. In the resulting configuration, reduced graphene offers continuous conductive channels for electron/ion transfer and high specific surface area to accommodate the volume expansion of copper ferrites. Consequently, the sheet-on-sheet CuFeO₂@rGO electrode exhibits a high reversible capacity (587 mAh g⁻¹ after 100 cycles at 200 mA g⁻¹). In particular, Cu/CuFe₂O₄@rGO hybrid, which combines the advantages of nano-copper and reduced graphene, manifests a significant enhancement in lithium storage properties. It reveals superior rate capability (723 mAh g⁻¹ at 800 mA g⁻¹; 560 mAh g⁻¹ at 3200 mA g⁻¹) and robust cycling capability (1102 mAh g⁻¹ after 250 cycles at 800 mA g⁻¹). This unique structure design provides a strategy for the development of multivalent metal oxides in lithium storage device applications.

The interlayer interaction of vertically stacked heterojunctions is very sensitive to the interlayer spacing, which will affect the coupling between the monolayers and allow band structure modulation. Here, with the aid of density functional theory (DFT) calculations, an interesting phenomenon is found that MoS₂-WS₂, MoS₂-WSe₂, and WS₂-WSe₂ heterostructures turn into direct-gap semiconductors from indirect-gap semiconductors with increasing the interlayer space. Moreover, the electronic structure changing process with interlayer spacing of MoS₂-WS₂, MoS₂-WSe₂, and WS₂-WSe₂ is different from each other. With the help of variable-temperature spectral experiment, different electronic transition properties of MoS₂-WS₂, MoS₂-WSe₂, and WS₂-WSe₂ have been demonstrated. The transition transformation from indirect to direct can be only observed in the MoS₂-WS₂ heterostructure, as the valence band maximum (VBM) at the Γ point in the MoS₂-WSe₂ and WS₂-WSe₂ heterostructure is less sensitive to the interlayer spacing than those from the MoS₂-WS₂ heterostructure. The present work highlights the significance of the temperature tuning in interlayer coupling and advance the research of MoS₂-WS₂, MoS₂-WSe₂, and WS₂-WSe₂ based device applications.