Three-dimensional photonic crystal （PC） heterostructures with high quality are fabricated by using a pressure controlled isothermal heating vertical deposition technique. The formed heterostructures have higher qual...Three-dimensional photonic crystal （PC） heterostructures with high quality are fabricated by using a pressure controlled isothermal heating vertical deposition technique. The formed heterostructures have higher quality, such as deeper band gaps and sharper band edges, than the heterostructures reported so far. Such a significant improvement in quality is due to the introduction of a thin TiO2 buffer layer between the two constitutional PCs. It is revealed that the disorder caused by lattice mismatch is successfully removed if the buffer layer is used once. As a result, the formed heterostructures possess the main features in the band gap of constitutional PCs. The crucial role of the thin buffer layer is also verified by numerical simulations based on the finite-difference time-domain technique.展开更多
Photonic crystal heterostructures containing two materials and/or two lattice constants are synthesized using the colloids of polystyrene and polymethyl methacrylate by a self-assembling technique. These direct hetero...Photonic crystal heterostructures containing two materials and/or two lattice constants are synthesized using the colloids of polystyrene and polymethyl methacrylate by a self-assembling technique. These direct heterostructures with double stop band are infiltrated with zinc oxide by sol-gel method, followed by the removal of the original polymer template by a wet-etching process to result in inverse heterostructures made of zinc oxide. A red shift in the wavelength of stop bands is observed when the crystal is infiltrated with zinc oxide and a blue shift after inversion, in concurrence with the changes in the effective index of the structure. The stop band is also calculated to extract the number of layers and the extinction co-efficient contributing to the heterostructure. This structure made by a room-temperature low-cost technique produces a sparsely-filled zinc oxide crystal with a single refractive index but containing two different periodicities in a layered arrangement that can be used as a lab-on-a-chip for dual- or multi-wavelength sensing applications.展开更多
A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uni...A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uniform surface over a large area can be produced rapidly using a minute quantity of suspension and without any additional equipment. By controlling the inclined angle, we can fabricate colloidal crystals with diverse numbers of layers. A colloidal crystal double-heterostructure （composed of three different colloidal photonic crystals） can be rapidly fabricated with this method. Both experimental and simulation results show that the photonic band gap of the double-heterostructure is not a simple superposition of that of the compositional colloidal crystals along the stacking direction.展开更多
Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to...Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to split the solar spectrum for hybrid photovoltaic/thermal solar applications.Here,we designed an efficient solar spectrum optical filter based on a cermet layer,Si/SiO_(2)1D photonic crystal,and top heterostructure layer.Compared with 1D photonic crystal structure,the 1D photonic crystal heterostructure with top YSZ layer can realize the reflectance of greater than 92%in PV band and the low average reflectance in two thermal bands by tuning the effective impedance of multilayer films.The enhanced reflectance in PV band results from the huge mismatching of impedance between free space and the heterostructure structure.The top dielectric layer can also be extended to other oxides.展开更多
Organic heterostructures with precisely defined compositions,architectures,and interfaces are considered promising building blocks for integrated optoelectronic devices.However,it remains a great challenge to rational...Organic heterostructures with precisely defined compositions,architectures,and interfaces are considered promising building blocks for integrated optoelectronic devices.However,it remains a great challenge to rationally design and synthesize a heterostructure with tunable performance for promising applications such as optoelectronic devices.Herein,we report a universal strategy for the synthesis of organic lateral heterostructures(OLHs)with tunable function and optical properties.We fabricated cocrystals based on the tunable intermolecular distance(dπ–πfrom 3.33 to 3.48Å)ofBenzo[ghi]perylene(BGP)-based driven by arene-perfluoroarene interaction or charge transfer interaction;these different components were selectively constructed into organic solid solution microwires or OLHs.Importantly,the solid solution microwires obtained could be epitaxially grown on the BGP-tetrabromophthalicanhydride trunk microwire to construct a series of OLHs microwires,which led to the successful demonstration of both photonic signal conversion and optical logic gate in all-color wavelength.This work gives a new insight into the fine synthesis of heterostructures with tunable structures/performances,providing predictable synthetic pathways to multifunctional organic heterostructures for the future realization of integrated optoelectronics.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10674051)the Program for Innovative Research Team of the Higher Education of Guangdong Province,China (Grant No 06CXTD005)the Key Program of Extracurricular Research in South China Normal University (SCNU),China (Grant No 08GDKC02)
文摘Three-dimensional photonic crystal （PC） heterostructures with high quality are fabricated by using a pressure controlled isothermal heating vertical deposition technique. The formed heterostructures have higher quality, such as deeper band gaps and sharper band edges, than the heterostructures reported so far. Such a significant improvement in quality is due to the introduction of a thin TiO2 buffer layer between the two constitutional PCs. It is revealed that the disorder caused by lattice mismatch is successfully removed if the buffer layer is used once. As a result, the formed heterostructures possess the main features in the band gap of constitutional PCs. The crucial role of the thin buffer layer is also verified by numerical simulations based on the finite-difference time-domain technique.
文摘Photonic crystal heterostructures containing two materials and/or two lattice constants are synthesized using the colloids of polystyrene and polymethyl methacrylate by a self-assembling technique. These direct heterostructures with double stop band are infiltrated with zinc oxide by sol-gel method, followed by the removal of the original polymer template by a wet-etching process to result in inverse heterostructures made of zinc oxide. A red shift in the wavelength of stop bands is observed when the crystal is infiltrated with zinc oxide and a blue shift after inversion, in concurrence with the changes in the effective index of the structure. The stop band is also calculated to extract the number of layers and the extinction co-efficient contributing to the heterostructure. This structure made by a room-temperature low-cost technique produces a sparsely-filled zinc oxide crystal with a single refractive index but containing two different periodicities in a layered arrangement that can be used as a lab-on-a-chip for dual- or multi-wavelength sensing applications.
基金Project supported by the Guangdong Province Natural Science Foundation, China (Grant No. 8151063101000030)the National Natural Science Foundation of China (Grant No. 10504008)the Key Project of Chinese Ministry of Education (Grant No. 209091)
文摘A self-assembly method, named the angle controlled inclined deposition method, is developed for fabricating well- ordered silica and polystyrene colloidal crystals. A high-quality colloidal crystal with a flat and uniform surface over a large area can be produced rapidly using a minute quantity of suspension and without any additional equipment. By controlling the inclined angle, we can fabricate colloidal crystals with diverse numbers of layers. A colloidal crystal double-heterostructure （composed of three different colloidal photonic crystals） can be rapidly fabricated with this method. Both experimental and simulation results show that the photonic band gap of the double-heterostructure is not a simple superposition of that of the compositional colloidal crystals along the stacking direction.
基金the National Natural Science Foundation of China(51871081,11674078 and 51971081)the Natural Science Foundation of Guangdong Province of China(2018A0303130033)+1 种基金Shenzhen Fundamental Research Project(JCYJ20170811155832192)Natural Scientific Research Innovation Foundation in Harbin Institute of Technology(HIT.NSRIF.2020060).
文摘Controlling the distribution of solar spectrum in different bands would boost the energy harvesting efficiency and optimize the energy dispatchability.1D photonic crystal with intrinsic optical band gap can be used to split the solar spectrum for hybrid photovoltaic/thermal solar applications.Here,we designed an efficient solar spectrum optical filter based on a cermet layer,Si/SiO_(2)1D photonic crystal,and top heterostructure layer.Compared with 1D photonic crystal structure,the 1D photonic crystal heterostructure with top YSZ layer can realize the reflectance of greater than 92%in PV band and the low average reflectance in two thermal bands by tuning the effective impedance of multilayer films.The enhanced reflectance in PV band results from the huge mismatching of impedance between free space and the heterostructure structure.The top dielectric layer can also be extended to other oxides.
基金support from the National Natural Science Foundation of China(grant nos.52173177 and 21971185)funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology(CIC-Nano)the“111”Project of the State Administration of Foreign Experts Affairs of China.
文摘Organic heterostructures with precisely defined compositions,architectures,and interfaces are considered promising building blocks for integrated optoelectronic devices.However,it remains a great challenge to rationally design and synthesize a heterostructure with tunable performance for promising applications such as optoelectronic devices.Herein,we report a universal strategy for the synthesis of organic lateral heterostructures(OLHs)with tunable function and optical properties.We fabricated cocrystals based on the tunable intermolecular distance(dπ–πfrom 3.33 to 3.48Å)ofBenzo[ghi]perylene(BGP)-based driven by arene-perfluoroarene interaction or charge transfer interaction;these different components were selectively constructed into organic solid solution microwires or OLHs.Importantly,the solid solution microwires obtained could be epitaxially grown on the BGP-tetrabromophthalicanhydride trunk microwire to construct a series of OLHs microwires,which led to the successful demonstration of both photonic signal conversion and optical logic gate in all-color wavelength.This work gives a new insight into the fine synthesis of heterostructures with tunable structures/performances,providing predictable synthetic pathways to multifunctional organic heterostructures for the future realization of integrated optoelectronics.
