Search for: All records

The infrared (IR) gas sensing technique is excellent for CO 2 gas detection systems that require high accuracy and safety standard; however, there is a significant barrier to its application due to its high cost and difficulty in miniaturization. CO 2 sensors that are functional within near- or short-wavelength IR have the potential to reduce this barrier. In this work, a highly sensitive plasmonic material based on nanostructured covellite copper sulfide (CuS), which exhibits desired localized surface plasmon resonance for surface-enhanced IR absorption (SEIRA) throughout near- and mid-IR ranges, was investigated. We prepared CuS thin films facilely in an additive manner based on a spatial successive ionic layer adsorption and reaction process at room temperature. The resulting CuS thin film possesses a structure consisting of hexagonal nanoflakes, and demonstrates significant SEIRA for 100 ppm CO 2 with an enhancement factor of 10 4 . 

Low-cost materials, scalable manufacturing, and high power conversion efficiency are critical enablers for large-scale applications of photovoltaic (PV) cells. Cu 2 ZnSn(S,Se) 4 (CZTSSe) has emerged as a promising PV material due to its low-cost earth-abundant nature and the low toxicity of its constituents. We present a compact and environmentally friendly route for preparing metal sulfide (metals are Cu, Zn, and Sn) nanoparticles (NPs) and optimize their annealing conditions to obtain uniform carbon-free CZTSSe thin films with large grain sizes. Further, the solution-stable binary NP inks synthesized in an aqueous solution with additives are shown to inhibit the formation of secondary phases during annealing. A laboratory-scale PV cell with a Al/AZO/ZnO/CdS/CZTSSe/Mo-glass structure is fabricated without anti-reflective coatings, and a 9.08% efficiency under AM1.5G illumination is demonstrated for the first time. The developed scalable, energy-efficient, and environmentally sustainable NP synthesis approach can enable integration of NP synthesis with emerging large-area deposition and annealing methods for scalable fabrication of CZTSSe PV cells.