DJL

An ultrathin HfS₂-based ultrasensitive phototransistor is systematically studied. Au-contacted HfS₂ phototransistors with ideal thickness ranging from 7 to 12 nm exhibit a high on/off ratio of ca. 10⁷, ultrahigh photoresponsivity over 890 A W⁻¹, and photogain over 2300. Moreover, the response time is strongly dependent on the back-gate voltage and shows a reverse trend for Au and Cr metals.

Two-dimensional (2D) lateral heterostructures have emerged as a hot topic in the fast evolving field of advanced functional materials , but their fabrication is challenging. The layer-structured WS₂ was theoretically demonstrated to be inert to oxidation except for the monolayer, which can be selectively oxidized owing to the simultaneous interaction of oxygen with both sides. Combined with the theoretical calculations, a new method was developed for the successful construction of 2D lateral heterostructures of WS₂/WO₃⋅H₂O in an ambient environment, based on a simple liquid-phase solution exfoliation. These lateral heterostructures of WS₂/WO₃⋅H₂O have interesting properties, as indicated by enhanced photocatalytic activity toward the degradation of methyl orange (MO).

Patchwork: 2D lateral WS₂/WO₃⋅H₂O heterostructures were successfully fabricated through the selective oxidation of monolayer WS₂. The presence of the heterostructures creates long-lived electron–hole pairs, which results in enhanced photocatalytic activity toward the degradation of methyl orange and higher photocurrent under visible-light irradiation.

Over the past decade, near-infrared (NIR)-emitting nanoparticles have increasingly been investigated in biomedical research for use as fluorescent imaging probes. Here, high-quality water-dispersible core/shell/shell PbS/CdS/ZnS quantum dots (hereafter QDs) as NIR imaging probes fabricated through a rapid, cost-effective microwave-assisted cation exchange procedure are reported. These QDs have proven to be water dispersible, stable, and are expected to be nontoxic, resulting from the growth of an outer ZnS shell and the simultaneous surface functionalization with mercaptopropionic acid ligands. Care is taken to design the emission wavelength of the QDs probe lying within the second biological window (1000–1350 nm), which leads to higher penetration depths because of the low extinction coefficient of biological tissues in this spectral range. Furthermore, their intense fluorescence emission enables to follow the real-time evolution of QD biodistribution among different organs of living mice, after low-dose intravenous administration. In this paper, QD platform has proven to be capable (ex vivo and in vitro) of high-resolution thermal sensing in the physiological temperature range. The investigation, together with the lack of noticeable toxicity from these PbS/CdS/ZnS QDs after preliminary studies, paves the way for their use as outstanding multifunctional probes both for in vitro and in vivo applications in biomedicine.

Low-dose in vivo near-infrared (NIR) fluorescence imaging is achieved by using carefully designed PbS/CdS/ZnS quantum dots (QDs), intensely emitting within the second biological window (1000–1350 nm). Moreover, preliminary studies both in vitro and in vivo have proven the lack of noticeable toxicity of these QDs. As an additional advantage, this NIR-fluorescence imaging platform has demonstrated useful multifunctionality, thus being capable, both ex vivo and in vitro, of high-resolution thermal sensing in the physiological temperature range.

In situ control of perovskite absorber properties enables a record-efficiency two-terminal monolithic perovskite-CIGS tandem thin-film solar cell.