Vanadium dioxide (VO 2 ) is a remarkable thermochromic material for application in adaptive infrared camouflage due to the reversible phase transition that is coupled with an abrupt change in infrared optical properties . However, the relatively high phase transition temperature and the unclear infrared optical modulation characteristics in the mid-infrared and far-infrared regions largely restrict its practical applications. Here, W-doped VO 2 nanoparticles were successfully prepared to reduce the transition temperature. When the effective doping amount of W was 1.70%, the transition temperature decreased to 43.2 °C. Importantly, the infrared properties of W-doped VO 2 nanoparticles were studied in both MWIR (3–5 μm) and LWIR (8–14 μm) thermal atmospheric windows, for the first time, which exhibited significant infrared optical changes, with emissivity variation of Δε = 0.17 and Δε = 0.28, respectively. These favorable results further promote the development of the adaptive camouflage.
Mu Ge,Tan Yimei,Bi Cheng,Liu Yanfei,Hao Qun,Tang Xin
Photodetection over a broad spectral range is necessary for multispectral sensing and imaging. Despite the fact that broadband single-element detectors with high performance have been demonstrated with various low-dimensional materials, broadband focal plane array imagers have been rarely reported. Here we propose a stacked lead sulfide/mercury telluride colloidal quantum dot photodetector configuration with optimized graded energy gaps. This architecture allows for ultrabroadband spectral response from 0.4 to 5.0 µm, with responsivity values of 0.23, 0.31, 0.83 and 0.71 A W −1 at 0.4, 0.7, 2.2 and 4.2 µm, respectively. We also fabricate a focal plane array imager with a resolution of 640 × 512, a low photoresponse non-uniformity down to 6% and a noise equivalent temperature difference as low as 34 mK. We demonstrate broadband imaging by simultaneously capturing both short-wave infrared and mid-wave infrared information, as well as multispectral imaging in the red, green, blue, short-wave infrared and mid-wave infrared channels, using a set of optical filters.
Biological visions have inspired the development of artificial vision systems with diverse visual functional traits, however, the detected wavelength is only in visible light between 0.4 and 0.78 μm, restricting their applications. Snakes generate a thermal image of animals due to pit organs for detecting and converting infrared, allowing them to accurately target predators or prey even under darkness. Inspired by natural infrared visualized snakes, we propose artificial vision systems with CMOS sensors-integrated upconverters to break visible light limitations to realize 3840 × 2160 ultra-high-resolution short-wave infrared (SWIR) and mid-wave infrared (MWIR) visualization imaging for the first time. Through colloidal quantum dot barrier heterojunction architecture design of infrared detecting units and the introduction of co-hosted emitting units, the luminance and upconversion efficiency reach up to 6388.09 cd m −2 and 6.41% for SWIR, 1311.64 cd m −2 and 4.06% for MWIR at room temperature. Our artificial vision systems broaden a wide spectrum of applications within infrared, such as night vision, agricultural science, and industry inspection, marking a significant advance in bioartificial vision.
危险品化学品经营许可证（带存储）