This letter reports on the fabrication and characterization of visible-blind ultraviolet photoconductors using single-crystal AlxGa1−xN layers deposited on basal plane sapphire substrates. With aluminum mole fractions ranging from 5% to 61%, the long-wavelength cutoff can be varied from 350 to 240 nm. Photoresponsitivities as high as several hundred amperes per watt were measured with 10 μm interelectrode spacing.
PNAM as an early-stage adjunctive therapy for nasal deformity correction is beneficial before primary cheiloplasty, but it is insufficient to maintain long-term nostril symmetry after primary cheiloplasty without nasal cartilage dissection.
All‐inorganic cesium lead halide perovskite nanocrystals have emerged as attractive optoelectronic nanomaterials due to their stabilities and highly efficient photoluminescence. High‐sensitivity photodetection covering a large spectral range from ultraviolet to near‐infrared is dominated by phototransistors. To overcome existing limitations in sensitivity and cost of state‐of‐the‐art systems, new‐style device structures and composite material systems are needed with low‐cost fabrication and high performance. Here, field‐effect phototransistors (FEpTs) based on CsPbBr3–PbS colloidal quantum dot heterostructure dominate to obtain a wide response spectral range and high performance. The large spectral detection spectrum is from 400 to 1500 nm similar to PbS quantum dots' response. It is worth mentioning that the device shows responsivity up to 4.5 × 105 A W−1, which is three orders of magnitude higher than the counterpart of individual material‐based devices. Furthermore, other high performance of hybrid CsPbBr3–PbS FEpTs including a short photoresponse time (less than 10 ms) is ascribed to the assistance of heterojunction on the transfer of photoexcitons. The solution‐based fabrication process and excellent device performance strongly underscore CsPbBr3–PbS quantum dot as a promising material for future photoelectronic applications.
The high-quality semipolar (112̅ 2) AlGaN epitaxial films have been obtained on m-plane sapphire by metal−organic chemical vapor deposition. X-ray rocking curve measurements show the full-width at halfmaximums of semipolar (112̅ 2)-oriented AlGaN films are 0.357°and 0.531°a long [112̅ 3̅ ] AlGaN and [11̅ 00] AlGaN , respectively. The fabricated semipolar AlGaN metal−semiconductor−metal solar-blind ultraviolet (UV) photodetector (PD) exhibits a high responsivity of 1842 A/W. The fast response and reliability of the UV PD are ensured via fast switching with a rise and decay time of 90 ms and 53(720) ms, respectively. The UV PD exhibits a significant reduction in the dark current, that is, from 100 μA to 780 fA at 10 V, using a simple wet chemical etching to modify the surface properties of materials. The photo-to-dark-current ratio value of the etched UV PD reaches 4 orders of magnitude higher than the unetched UV PD under 270 nm illumination. These are attributed to the fact that KOH wet etching assists in eliminating the surface states and reconstructing the surface oxides. This work might provide a new potential for the development of solar-blind UV PDs with high performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.