This paper reports a novel synthesis approach of bovine serum albumin (BSA) protein-templated ultrasmall (<2 nm) Ag nanocluster (NC) with strong singlet oxygen generation capacity for photodynamic therapy (PDT). An atomically precise BSA-Ag NC (i.e., 13 Ag atoms per cluster) is successfully synthesized for the first time by using NaOH-dissolved NaBH solution as the controlling reducing agent. The ubiquitous size of BSA-Ag NC results in unique behaviors of its photoexcited states as characterized by the ultrafast laser spectroscopy using time-correlated single photon counting and transient absorption techniques. In particular, triply excited states can be largely present in the excited BSA-Ag NC and readily sensitized molecular oxygen to produce singlet oxygen ( O ) with a high quantum efficiency (≈1.26 using Rose Bengal as a standard). This value is much higher than its Au analogue (i.e., ≈0.07 for BSA-Au NC) and the commonly available photosensitizers. Due to the good cellular uptake and inherent biocompatibility imparted by the surface protein, BSA-Ag NC can be applied as an effective PDT agent in generating O to kill cancer cell as demonstrated in this study.

In this review, we present an update on the methods for screening 2D materials suitable for valleytronic applications. We begin with an introduction to the field highlighting some of the latest findings and seminal works. Then we provide a brief background on the physics of valley- and layer- pseudospins in layered 2D materials such as transition metal dichalcogenides. This is followed by a detailed survey of a number of key techniques commonly employed to elucidate valley properties in such materials, highlighting in particular their capability for discriminating valley pseudospins, their key advantages and current limitations. Finally, we conclude by summarising the state-of-the-art assessing materials for valleytronic applications and point the reader to the current open questions that could have critical influence on the technological impact that may be derived from such materials.

Tri-cation and dual-anion mixed perovskites have been widely utilized in perovskite solar cell (PSC) applications due to their novel properties such as high absorption, high stability, and low cost. To commercialize the PSCs, further improving the device performance without detrimentally changing the device configuration is important at present. Herein, Au@SiO 2 nanoparticles (NPs) are introduced to modify the interface between mesoporous TiO 2 (mp-TiO 2 ) and mixed perovskite with increased main photovoltaic parameters of the device, resulting in a ≈29% enhancement of power conversion efficiency (PCE) from 15.8% to 20.3%. The origins of the enhancement have been studied by exploring the optical absorption, optical power distribution, and charge carrier behaviors within the system. The small perturbation transient photovoltage measurement exhibits prolonged charge carrier lifetimes after the Au@SiO 2 NPs incorporation, and time of flight photoconductivity measurement shows that charge carrier mobilities of this system are also enhanced. These characteristics make metallic nanostructures a promising functional material in facile tuning of the charge carriers transport and further boosting the PCE of the PSCs.

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Heterojunction solar cells of p-type cupric oxide (CuO) and n-type silicon (Si), p-CuO/n-Si, have been fabricated using conventional sputter and rapid thermal annealing techniques. Photovoltaic properties with an open-circuit voltage (V oc ) of 380 mV, short circuit current (J sc ) of 1.2 mA/cm 2 , and a photocurrent of 2.9 mA/cm 2 were observed for the solar cell annealed at 300°C for 1 min. When the annealing duration was increased, the photocurrent increased, but the V oc was found to reduce because of the degradation of interface quality. An improvement in the V oc resulting to a record value of 509 mV and J sc of 4 mA/cm 2 with a high photocurrent of~12 mA/cm 2 was achieved through interface engineering and controlling the phase transformation of CuO film. X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy analysis have been used to investigate the interface properties and crystal quality of sputter-deposited CuO thin film. The improvement in V oc is mainly due to the enhancement of crystal quality of CuO thin film and interface properties between p-CuO and n-Si substrate. The enhancement of photocurrent is found to be due to the reduction of carrier recombination rate as revealed by transient photovoltage spectroscopy analysis.

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The present review rationalizes the significance of the metal oxide semiconductor (MOS) interfaces in the field of photovoltaics and photocatalysis. This perspective considers the role of interface science in energy harvesting using organic photovoltaics (OPVs) and dye-sensitized solar cells (DSSCs). These interfaces include large surface area junctions between photoelectrodes and dyes, the interlayer grain boundaries within the photoanodes, and the interfaces between photoactive layers and the top and bottom contacts. Controlling the collection and minimizing the trapping of charge carriers at these boundaries is crucial to overall power conversion efficiency of solar cells. Similarly, MOS photocatalysts exhibit strong variations in their photocatalytic activities as a function of band structure and surface states. Here, the MOS interface plays a vital role in the generation of OH radicals, which forms the basis of the photocatalytic processes. The physical chemistry and materials science of these MOS interfaces and their influence on device performance are also discussed.

With their high‐surface‐to‐volume ratio, nanofibers have been postulated to increase interactions between nanofibrous materials and targeted substrates, which are helpful to overcome many obstacles and enhance the efficiency in a diverse number of applications. Over the past decade, many studies have been published on the fabrication of nanofibers and their applications in various fields. In this review, novel biological, chemical, and electrical characteristics of nanofibers as well as their recent status and achievements in medicine, chemistry, and electronics are analyzed. It is found that nanofibers can induce fast regeneration of many tissues/organs in medical applications and improve the efficiency of many chemical and electronics applications.