Silicon-based complementary metal oxide semiconductor (CMOS) devices have dominated the technological revolution in the past decades. With increasing demands in machine vision, autonomous driving, and artificial intelligence, silicon CMOS imagers, as the major optical information input devices, face great challenges in spectral sensing ranges. In this paper, we demonstrate the development of CMOS-compatible infrared colloidal quantum-dot (CQD) imagers in the broadband short-wave and mid-wave infrared ranges (SWIR and MWIR, 1.5–5 μm). A new device architecture of trapping-mode detectors is proposed, fabricated, and demonstrated with lowered darkcurrents and improved responsivity. The CMOS-compatible fabrication process is completed with two-step sequential spin-coating processes of intrinsic and doped HgTe CQDs on an 8 in. CMOS readout wafer with photoresponse non-uniformity (PRNU) down to 4%, dead pixel rate of 0%, external quantum efficiency up to 175%, and detectivity as high as 2 × 1011 Jones for extended SWIR at 300 K and 8 × 1010 Jones for MWIR at 80 K. Both SWIR images and MWIR thermal images are demonstrated with great potential for semiconductor inspection, chemical identification, and temperature monitoring.

The growth and stress vs. strain characterization of the silver solid solution phase with indium Silver solid solution phase with indium has been discovered to have great mechanical properties and anti-tarnishing property, as shown in the results of our previous study. It is important to know the stress vs. strain curve before adopting this material in industrial applications. The growth of the homogeneous silver solid solution phase with indium is first described. The X-ray diffraction (XRD) patterns and scanning electron microscope/energy dispersive X-ray spectroscopy (SEM/EDX) results are reported to verify the chemical composition of silver solid solution phase with indium samples. Based on the results, one could reversely determine the indium element composition in (Ag)exxIn solid solution by examining the lattice constant value using XRD for unknown compositions. The preparation of ASTM tensile test samples and tensile test experimental setting are explained in details. The intrinsic mechanical material properties of silver solid solution phase with indium, i.e., characteristic stress vs. strain curves, are presented and analyzed, with pure silver stress vs. strain curve in comparison. According to the experimental results, silver solid solution phase with indium exhibits low yield strength, high ultimate tensile strength, and large elongation value before fracture, compared to pure silver. In addition, fractography of the fracture surface of the tested sample has been studied to confirm the superior ductility of silver solid solution phase with indium. These superior mechanical properties may bring silver solid solution phase with indium new applications in various industries such as electronics and brazing.

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Tarnishing of silver objects have been real issues throughout millennia of human civilization history due to the fact that silver is very susceptible to sulfur element and can easily get tarnished by sulfur-containing gases. Over the past several decades, researchers have been studying mechanisms of tarnishing phenomena and tried to formulate and develop anti-tarnishing engineering solutions for various fields of applications, including jewelry, catalysts, electronics and optics. Recently, our research group demonstrated that silver-indium solid solutions possessed excellent anti-tarnishing property by quantitative experimental studies. However, the anti-tarnishing mechanism in silver-indium binary system is still unknown. In this paper, anti-tarnishing mechanism in silverindium binary system is studied by a semi-quantum-mechanical approach. Silver-indium thin film were systematically examined by several experimental approaches in order to study their crystallography and surface properties thermodynamically. An original semi-quantum-mechanical approach was introduced for calculating the Hard and Soft Acids and Bases quantifiable parameters based on conceptual DFT formalization and incorporated with the Hammer-Nørskov d-band model, namely, absolute electronegativity and chemical hardness. Finally, the discovery of increasing absolute electronegativity and chemical hardness can be used to theoretically interpret the most fundamental mechanism behind the mystery of anti-tarnishing phenomenon in the silver-indium binary system.

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