Gallium antimonide(GaSb)-based nanostructures have been reported via various vapor-phase synthetic routes while there is not a report on the growth of GaSb nanostructures via a complete one-step solution-phase synthetic strategy.Herein we report the design and synthesis of tadpole-like Ga/GaSb nanostructures by a one-step solution-phase synthetic route typically from the precursors of commercial triphenyl antimony(Sb(Ph)_(3))and trimethylaminogallium(Ga(NMe_(2))_(3))at 260°C in 1-octadecene.The GaSb nanocrystals are grown based on a solution–liquid–solid(SLS)mechanism with zinc blende phase,and their size and shape can be controlled in the procedures via manipulating the reaction conditions.Meanwhile,the tadpole-like Ga/GaSb nanostructures can be applied for the fabrication of a GaSb/Si nanostructured heterojunction-like photodetector over silicon wafer,which demonstrates excellent photoresponse and detection performances from wavelength of 405 to 1,064 nm with high photoresponding rate.Typically,the photodetector exhibits a high responsivity of 18.9 A·W^(−1),a superior detectivity of 1.1×10^(13)Jones,and an ultrafast response speed of 44 ns.The present work provides a new strategy to group III–V antimonide-based semiconducting nanostructures that are capable for the fabrication of photodetector with broadband,high-detectivity,and high-speed photodetecting performances.
Huanran LiSu YouYongqiang YuLin MaLi ZhangQing Yang
Solution-phase hydrogen reduction(Sp HR)was introduced into V_(2)O_(3)preparation to overcome disadvantages of traditional reduction roasting,which include a long process,high energy consumption,and generation of pollution.The research mainly focuses onφ-pH diagrams and kinetics of SpHR.Thermodynamic analysis ofφ-pH diagrams for the V-H_(2)O system demonstrates that V_(2)O_(3)preparation via Sp HR requires a high temperature,a high vanadium concentration,and sufficient hydrogen in acidic solution.Kinetic analyses show that the activation energy of V_(2)O_(3)preparation via SpHR is 38.0679 k J/mol,indicating that the reduction is controlled by a combination of interfacial chemical reaction and internal diffusion.Effects of H;partial pressure(slope K=0.05246)on the reaction rate is not as significant as the vanadium concentration(K=1.58872).V_(2)O_(3)crystals with a purity of 99.59%and a vanadium precipitation rate of 99.83%were obtained under the following conditions:pH=5-6,c(V_(2)O_(3))=0.5 mol/L,p(H;)=4 MPa,m(PdCl;)=10 mg,T=250℃,and t=2.5 h.
H2S can cause multiple diseases and poses a great threat to human health.However,the precise detection of extremely toxic H2S at room temperature is still a great challenge.Here,a facile solvent evaporation induced aggregating assembly(EIAA)method has been applied for the production of ordered mesoporous carbon(OMCs)in an acidic THF/H2 O solution with high-molecular-weight poly(ethylene oxide)-b-polystyrene(PEO-b-PS)copolymers as the structure-directing agent,formaldehyde and resorcinol as carbon precursors.Along with the continuous evaporation of THF from the mixed solution,cylindrical micelles are formed in the solution and further assemble into highly ordered mesostructure.The obtained OMCs possesses a two-dimensional(2 D)hexagonal mesostructure with uniform and large pore diameter(~19.2 nm),high surface area(599 m2/g),and large pore volume(0.92 cm3/g).When being used as the resonant cantilever gas sensor for room-temperature H2S detection,the OMCs has delivered not only a superior gas sensing performance with ultrafast re s ponse(14 s)and recovery(21 s)even at low concentration(2 ppm)but also an excellent selectivity toward H2S among various common interfering gases.Moreover,the limit of detection is better than 0.2 ppm,indicating its potential application in environmental monitoring and health protection.
Jiawei NiTao ZhaoLei TangPengpeng QiuWan JiangLianjun WangPengcheng XuWei Luo
The synthesis of high quality all-inorganic perovskite nanowires needs the harsh conditions,complex process and precision instruments,which are not beneficial to their extensive application.Here,all-inorganic perovskite ce- sium lead bromine (CsPbBr3)nanowires (NWs)are demonstrated with the combination of solution-phase process and halide exchange technology.A metal-semiconductor-metal structure CsPbBr3 nanowire photodetector was prepared, which showed a detectivity as high as 1.7×10^11 cm Hz^1/2W^-1 (Jones)with rapid response time (The rise and decay time are 10ms and 22 ms,respectively).Moreover,our photodetectors have high stability under ultraviolet (UV)light,high temperature and humidity.
Epitaxial heterostructures based on organicinorganic hybrid perovskites and two-dimensional materials hold great promises in optoelectronics, but they have been prepared only via solid-state methods that restricted their practical applications. Herein, we report cubic-phased MAPbBr3(MA=CH3NH3+) nanocrystals were epitaxially deposited on trigonal/hexagonal-phased MoS2 nanosheets in solution by facilely tuning the solvation conditions. In spite of the mismatched lattice symmetry between the square MAPbBr3(001) overlayer and the hexagonal MoS2(001) substrate, two different aligning directions with lattice mismatch of as small as 1% were observed based on the domainmatching epitaxy. This was realized most likely due to the flexible nature and absence of surface dangling bonds of MoS2 nanosheets. The formation of the epitaxial interface affords an effective energy transfer from MAPbBr3 to MoS2, and as a result, paper-based photodetectors facilely fabricated from these solution-dispersible heterostructures showed better performance compared to those based on MoS2 or MAPbBr3 alone. In addition to the improved energy transfer and light adsorption, the use of MoS2 nanosheets provided flexible and continuous substrates to connect the otherwise discrete MAPbBr3 nanocrystals and achieved the better film forming ability. Our work suggests that the scalable preparation of heterostructures based on organic-inorganic hybrid perovskites and 2D materials via solution-phase epitaxy may bring about more opportunities for expanding their optoelectronic applications.
