Light-triggered two-dimensional lateral homogeneous p-n diodes for opto-electrical interconnection circuits

The realization of light-triggered devices where light is used as external stimulus to control the device performances is a long-standing goal in modern opto-electrical interconnection circuits.In this work,it reveals that light illumination can induce the formation of p-n junctions along two-dimensional conduction channels.The results indicate that the dominant charge carrier type and density in black phosphorus(BP)conduction channel can be effectively modulated by the underlying cadmium sulfide(CdS)photogate layer under light illumination.This enables flexible switching of the working state between BP resistor and BP p-n diode in the designed semi-photo-gate transistor(SPGT)devices when switching the light on and off(ultra-low threshold light power).Simultaneously,the achieved BP p-n junctions also exhibit ultra-high photoresponsivity and evident photovoltaic properties.That is to say,light can be employed as external stimulus to define the BP p-n junctions,and in turn the p-n junctions will further convert the light into electrical power,showing all-in-one opto-electrical interconnection properties.Moreover,the SPGT device architecture is also applicable for construction of other ambipolar semiconductor-based(WSe2-and MoTe2-based)p-n diodes.Such universal all-in-one light-triggered lateral homogeneous pn junctions with ultra-low energy consumption should open a new pathway toward novel optoelectronic devices and deliver various new applications.

A rationally designed cancer vaccine based on NIR-II fluorescence image-guided light-triggered remote control of antigen cross-presentation and autophagy

Cancer vaccines represent a promising immunotherapeutic treatment modality.The promotion of cross-presentation of extracellular tumor-associated antigens on the major histocompatibility complex(MHC) class I molecules and dendritic cell maturation at the appropriate time and place is crucial for cancer vaccines to prime cytolytic T cell response with reduced side effects.Current vaccination strategies,however,are not able to achieve the spatiotemporal control of antigen cross-presentation.Here,we report a liposomal vaccine loading the second near-infrared window(NIR-II,1000—1700 nm) fluorophore BPBBT with an efficient photothermal conversion effect that offers an NIR-light-triggered endolysosomal escape under the imaging guidance.The NIR-II image-guided vaccination strategy specifically controls the cytosolic delivery of antigens for cross-presentation in the draining lymph nodes(DLNs).Moreover,the photothermally induced endolysosomal rupture initiates autophagy.We also find that the adjuvant simvastatin acts as an autophagy activator through inhibiting the PI3K/AKT/m TOR pathway.The light-induced autophagy in the DLNs together with simvastatin treatment cooperatively increase MHC class II expression by activating autophagy machinery for dendritic cell maturation.This study presents a paradigm of NIR-II image-guided light-triggered vaccination.The approach for remote control of antigen cross-presentation and autophagy represents a new strategy for vaccine development.

Light-triggered plasmonic vesicles with enhanced catalytic activity of glucose oxidase for programmable photothermal/starvation therapy

Glucose oxidase(GOx)-based nanotheranostic agents hold great promise in tumor starvation and its synergistic therapy. Self-assembled plasmonic gold vesicles(GVs) with unique optical properties, large hollow cavity, and strong localized surface plasmon resonance, can be used as multi-functional nanocarriers for synergistic therapy. Herein,GOx-loaded GVs(GV-GOx) were developed for light-triggered GOx release as well as enhanced catalytic activity of GOx, achieving programmable photothermal/starvation therapy. Under near-infrared laser irradiation, the GV-GOx generated strong localized hyperthermia due to plasmon coupling effect of GVs, promoting the release of encapsulated GOx and increasing its catalytic activity, resulting in enhanced tumor starvation effect. In addition, the high photothermal effect improved the cellular uptake of GV-GOx and allowed an efficient monitoring of synergistic tumor treatment via photoacoustic/photothermal duplex imaging in vivo. Impressively, the synergistic photothermal/starvation therapy demonstrated complete tumor eradication in 4 T1 tumorbearing mice, verifying superior synergistic anti-tumor therapeutic effects than monotherapy with no apparent systemic side effects. Our work demonstrated the development of a light-triggered nanoplatform for cancer synergistic therapy.

The visible light-triggered nonvolatile memory performances in melamine-decorated <110>-oriented lead halide perovskites: A photo-responsive structural evolution insight

The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energysaving memories.Herein,new<110>-oriented perovskites using single template melamine,i.e.,[(MLAI-H_(2))(PbX_(4))]_n(X=Br (α-1),Cl (α-2),MLAI=melamine) have been prepared and their structures upon irradiation of visible light have been investigated.They have been fabricated as nonvolatile memory devices with structures of ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag (device-1:X=Br,device-2:X=Cl),which can exhibit unique visible light-triggered binary nonvolatile memory performances.Interestingly,the silent or working status can be monitored by visible chromisms.Furthermore,the light-triggered binary resistive switching mechanisms of these ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag memory devices have been clarified in terms of EPR,fluorescence,and single-crystal structural analysis.The presence of light-activated traps in<110>-oriented[(MLAI-H_(2))(PbX_(4))]_n perovskites are dominated in the appearance of light-triggered resistive switching behaviors,based on which the inverted internal electrical fields can be established.According to the structural analysis,the more distorted PbX_6octahedra,higher corrugated<110>-oriented perovskite sheets,and more condensed organic-inorganic packing in Br-containing perovskite are beneficial for the stabilization of light-activated traps,which lead to the better resistive switching behavior of device-1.This work can pave a new avenue for the establishment of novel energy-saving nonvolatile memorizers used in aerospace or military industries.

±800kV楚雄换流站光流触发晶闸管故障分析及措施

换流阀是高压直流系统的核心部分,而晶闸管则是换流阀的核心元件,是实现整流和逆变的关键。±800 kV楚雄换流站换流阀采用的是T2563 N80T-S34型光触发晶闸管(light-triggered thyristor,LTT)。LTT具有集成过压保护功能,失效率低。但自2012年4月22日云广直流系统第4阶段孤岛调试结束至5月10日,累计有8只换流阀晶闸管失效。文中针对短时间内多个晶闸管失效这一情况,介绍了±800 kV楚雄换流站换流阀的基本结构和组成元件;阐明了LTT的导通原理和失效机理;结合晶闸管故障情况、晶闸管失效时的系统暂态工况分析、换流阀相关参数对比分析以及避雷器动作分析,总结了造成LTT失效的原因;并提出了解决办法和预防措施。

Synergistic antibacterial activity of physical-chemical multi-mechanism by TiO2 nanorod arrays for safe biofilm eradication on implant

Treatment of implant-associated infection is becoming more challenging,especially when bacterial biofilms form on the surface of the implants.Developing multi-mechanism antibacterial methods to combat bacterial biofilm infections by the synergistic effects are superior to those based on single modality due to avoiding the adverse effects arising from the latter.In this work,TiO2 nanorod arrays in combination with irradiation with 808 nearinfrared(NIR)light are proven to eradicate single specie biofilms by combining photothermal therapy,photodynamic therapy,and physical killing of bacteria.The TiO2 nanorod arrays possess efficient photothermal conversion ability and produce a small amount of reactive oxygen species(ROS).Physiologically,the combined actions of hyperthermia,ROS,and puncturing by nanorods give rise to excellent antibacterial properties on titanium requiring irradiation for only 15 min as demonstrated by our experiments conducted in vitro and in vivo.More importantly,bone biofilm infection is successfully treated efficiently by the synergistic antibacterial effects and at the same time,the TiO2 nanorod arrays improve the new bone formation around implants.In this protocol,besides the biocompatible TiO2 nanorod arrays,an extra photosensitizer is not needed and no other ions would be released.Our findings reveal a rapid bacteria-killing method based on the multiple synergetic antibacterial modalities with high biosafety that can be implemented in vivo and obviate the need for a second operation.The concept and antibacterial system described here have large clinical potential in orthopedic and dental applications.

Light-responsive nanomedicine for cancer immunotherapy

Immunotherapy emerged as a paradigm shift in cancer treatments, which can effectively inhibit cancer progression by activating the immune system. Remarkable clinical outcomes have been achieved through recent advances in cancer immunotherapy, including checkpoint blockades, adoptive cellular therapy, cancer vaccine, and tumor microenvironment modulation. However, extending the application of immunotherapy in cancer patients has been limited by the low response rate and side effects such as autoimmune toxicities. With great progress being made in nanotechnology, nanomedicine has been exploited to overcome biological barriers for drug delivery. Given the spatiotemporal control,light-responsive nanomedicine is of great interest in designing precise modality for cancer immunotherapy. Herein, we summarized current research utilizing light-responsive nanoplatforms to enhance checkpoint blockade immunotherapy, facilitate targeted delivery of cancer vaccines, activate immune cell functions, and modulate tumor microenvironment. The clinical translation potential of those designs is highlighted and challenges for the next breakthrough in cancer immunotherapy are discussed.