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Piezochromic luminescent materials have shown great potential in advanced optoelectronic applications. However, most of luminescent materials usually undergo emission quenching under external stimuli. Herein, we demonstrate for the first time that the photoluminescence of carbon dots (CDs) confined within sodium hydroxide can be enhanced when high pressure is applied. They exhibit a 1.6-fold fluorescence enhancement compared with pristine CDs. Importantly, the enhanced fluorescence intensity can be retained after the release of pressure to ambient conditions. A combination of experimental analysis and theoretical simulations indicates that such an enhanced emission is mainly attributed to the strong confinement resulting from the sodium hydroxide matrix, which can separate the CDs spatially and restrict the nonradiative pathway. These results provide a rational strategy for manipulating the optical properties of CDs with enhanced and retainable photoluminescence (PL) performance, thus opening up a venue for designing luminescent CDs-based materials.

Phosphorescent carbon nanodots (CNDs) have various attractive properties and potential applications, but it remains a formidable challenge to achieve large-scale phosphorescent CNDs limited by current methods. Herein, a large-scale synthesis method for phosphorescent CNDs has been demonstrated via precursors’ self-exothermic reaction at room temperature. The as-prepared CNDs show fluorescence and phosphorescence property, which are comparable with that synthesized by solvothermal and microwave method. Experimental and computational studies indicate that exotic atom doped sp2 hybridized carbon core works as an emissive center, which facilities the intersystem crossing from singlet state to triplet state. The CNDs show phosphorescence with tunable lifetimes from 193 ms to 1.13 s at different temperatures. The demonstration of large-scale synthesis of phosphorescent CNDs at room temperature opens up a new window for room temperature fabrication phosphorescent CNDs.

Long linear carbon chains (LLCCs) with sp hybridization are emerging as a promising realization of carbyne, which has been predicted to be a semiconducting nanowire with tunable electronic properties by external stimuli. Here, the LLCCs confined in double-walled carbon nanotubes have been studied by resonant Raman spectroscopy and density functional theory under high pressure. Our results indicate that the band gap linearly decreases from 2.18 to 1.73 eV as pressure increases, which can be explained by the reduction of the bond length alternation of the chains due to the enhanced interaction between the inner tube and the carbon chain. Furthermore, both our experiment and theoretical calculations show that an irreversible pressure-induced interlinkage between inner tubes and carbon chains forms at the system collapse pressure. In our study this value is of 20 GPa, which is determined by the inner tube diameter. These findings provide important insights for tuning the structural and electronic properties of carbon chains, thus may open new perspectives for the realization of nanoscale cables and devices.

We establish a novel carbon phase in purely sp3-bonded networks with a 14-atom orthorhombic unit cell, termed C14 carbon, by swarm structural searches. This novel carbon phase is dynamically and mechanically stable under ambient conditions. The C14 carbon exhibits a high bulk modulus of 407 GPa and Vickers hardness of 84.3 GPa, which are comparble to those of diamond. Simulated X-ray diffraction pattern is in satisfactory agreement with the previously unresolved diffraction peaks found in detonation soot samples. Interestingly, electronic band structure calculations reveal that the C14 carbon is a semiconductor with a direct band gap of around 4.60 eV. These results establish a novel carbon phase with outstanding mechanical and electronic properties and offer insights for further exploring other carbon allotropes.

Lead halide perovskites have recently emerged as promising materials for various optoelectronic applications. However, realizing lead-free and stable perovskites with broad-band emission for the fa...

Carbyne, as the truly one-dimensional carbon allotrope with sp-hybridization, has attracted significant interest in recent years, showing potential applications in next-generation molecular devices due to its ultimate one-atom thinness. Various excellent properties of carbyne have been predicted, however, free-standing carbyne sample is extremely unstable and the corresponding experimental researches and modifications are under-developed compared to other known carbon allotropes. The synthesis of carbyne has been slowly developed for the past decades. Recently, there have been several breakthroughs in in-situ synthesis and measurement of carbyne related materials, as well as the preparation of ultra-long carbon chains toward infinite carbyne. These progresses have aroused widespread discussion in the academic community. In this review, the latest approaches in the synthesis of sp carbon are summarized. We then discuss its extraordinary properties, including mechanical, electronic, magnetic, and optical properties, especially focusing on the regulations of these properties. Finally, we provide a perspective on the development of carbyne.

Flexible and stretchable electronic devices have attracted considerable interests for their significant impact on future human life. Here, we reported an intrinsically stretchable and transparent alternating current electroluminescent device driven with a triboelectric nanogenerator. The electroluminescent layer of ZnS:Cu-embedded-polydimethylsiloxane was sandwiched with two electrodes consisted of single-walled carbon nanotubes. The alternating current electroluminescent device is stretchable, flexible and transparent, and exhibits bright and durable electroluminescence under quasi-static and dynamic deformation at the tensile strain up to 100%. The integrated system displays a stable output intensity under periodically mechanical stimuli, and retains 98.4% of its original luminance after continuous operation for 1000 cycles. This hybrid system might find its future applications in soft robotics, human-machine interfacing, and self-powered monitoring.

Herein, the negative photoconductivity (NPC) effect has been observed in nanodiamonds (NDs) for the first time, and with illumination under a 660 nm laser lamp, the conductivity of the NDs decreases significantly. The NPC effect has been attributed to the trapping of carriers by the absorbed water molecules on the ND surfaces. A humidity sensor has been constructed based on the NPC effect of the NDs, and the sensitivity of the sensor can reach 106%, which is the highest value ever reported for carbon-based humidity sensors.

Three-dimensional (3D) printing has been playing an important role in diverse areas in medicine. In order to promote the development of tissue engineering, this study attempts to fabricate tissue engineering scaffolds using the inkjet printing technology. Sodium alginate, exhibiting similar properties to the native human extracellular matrix (ECM), was used as bioink. The jetted fluid of sodium alginate would be gelatinized when printed into the calcium chloride solution. The characteristics of the 3D-printed sodium alginate scaffold were systematically measured and analyzed. The results show that, the pore size, porosity and degradation property of these scaffolds could be well controlled. This study indicates the capability of 3D bioprinting technology for preparing tissue engineering scaffolds.

Nanodiamonds (NDs) have excellent mechanical and optical properties, large surface area, easy bioconjugation and high biocompatibility, which makes them especially appealing for various potential applications. In recent years, NDs have received considerable attention in nanomedicine, and some noteworthy progress has been achieved. This review summarizes the synthetic routes and unique properties of NDs. In addition, the recent progress of NDs in nanomedical applications, including bioimaging, drug delivery and biosensing, is also discussed. We further provide an outlook towards the future developments and applications of NDs.

Poor stability as an essential issue of metal halide perovskites (MHPs), limits their further applications in displaying and lighting. Among multicolor luminous MHPs, the development of blue luminous perovskite lags far behind that of red and green emission. Herein, a “MAPbBrxCl3-x quantum dots (QDs) in Pb(OH)Br” strategy is proposed, fabricating stable MAPbBrxCl3-x@Pb(OH)Br with the emission wavelength of 435–485 nm. Experimental characterizations indicate that cubic MAPbBrxCl3-x transforms into rectangular MAPbBrxCl3-x@Pb(OH)Br with the assistance of methylamine vapor. The as-prepared MAPbBrxCl3-x@Pb(OH)Br shows high stability of water, light, heat and organic solvents, which can emit bright emission even they are immersed in water for 6 months. In addition, anion exchange induced spectral shift of the MHPs are also suppressed due to the chemical inertness of Pb(OH)Br. Notably, this strategy is also applied to all inorganic halide perovskites. Blue light-emitting devices (LEDs) based on the MAPbBrxCl3-x@Pb(OH)Br have been demonstrated, which can run stably for over 8 h with brightness exceeding 1000 cd/m2 in a humid environment.

The various luminescent properties of carbon nanodots (CDs) reveal fascinating applications in several areas. Here, bright and multicolor chemiluminescence (CL) is realized from CDs, whose CL quantum yield can be optimized by adjusting the energy level alignment between the CDs and 1,2‐dioxetanedione intermediate generated from the reaction of peroxalate and hydrogen peroxide. A CL quantum yield of 9.32 × 10−3 Einsteins mol−1, maximal luminance of 3.28 cd m−2, and lifetime of 186.4 s are achieved in red CDs, all of which are the best values ever reported for CDs. As a proof‐of‐concept prototype, a high‐quality information encryption strategy is established via CD based CL imaging techniques by virtue of the high brightness and multicolor CL.

Nanodiamonds have outstanding mechanical properties, chemical inertness, and biocompatibility, which give them potential in various applications. Current methods for preparing nanodiamonds often lead to products with impurities and uneven morphologies. We report a two-step high-pressure high-temperature (HPHT) method to synthesize nanodiamonds using naphthalene as the precursor without metal catalysts. The grain size of the diamonds decreases with increasing carbonization time (at constant pressure and temperature of 11.5 GPa and 700 °C, respectively). This is discussed in terms of the different crystallinities of the carbon intermediates. The probability of secondary anvil cracking during the HPHT process is also reduced. These results indicate that the two-step method is efficient for synthesizing nanodiamonds, and that it is applicable to other organic precursors.

Current ULSI circuits have features with dimensions in the nanoscale region. As the critical dimension shrinks, Cu BEOL systems face reliability impacts. Alloying has been proved to be a promising technique to retard grain boundary electro-migration (EM). In this paper, dilute Cu Alloys such as Cu-Al, Cu-Mn for dual-damascene interconnect applications have been investigated. The alloy chosen principle for nanoscale interconnects has been discussed. The ultrahigh purity copper alloy target properties including purity, alloy composition, grain size and sputtering performance were investigated, to lay the foundation for the application of the large-size ultrahigh purity copper alloy target used for 300mm wafer fabrication. The relationships between deposited film behaviors and sputtering target properties in some applications were also discussed. In order to acquire high quality thin film, the properties of sputtering target such as alloy composition homogeneity, grain size and uniformity et al. have to be well controlled by proper fabrication techniques.