Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable f...Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable for their applications in many fields.Hence,impeding anion exchange is important for improving the composition stability of inorganic lead halide perovskite NCs.Herein,CsPb X3(X=Cl,Br)NCs are coated with Cs4PbX6 shell to impede anion exchange and reduce anion mobility.The Cs4PbX6 shell is facily fabricated on CsPbX3 NCs through high temperature injection method.Anion exchange experiments demonstrate that the Cs4 PbX6 shell completely encapsulates CsPbX3 NCs and greatly improves the composition stability of CsPbX3 NCs.Moreover,our work also sheds light on the potential design approaches of various heterostructures to expand the application of CsPbM3(M=Cl,Br,I)NCs.展开更多
Halide perovskite （CsPbX3, X = C1, Br, or I） quantum dots have received increasing attention as novel colloidal nanocrystals （NCs）. Accurate control of emission bands and NC morphologies are vital prerequisites fo...Halide perovskite （CsPbX3, X = C1, Br, or I） quantum dots have received increasing attention as novel colloidal nanocrystals （NCs）. Accurate control of emission bands and NC morphologies are vital prerequisites for most CsPbX3 NC practical applications. Therefore, a facile method of synthesizing CsPbX3 （X = C1, Br, or I） NCs in the nonpolar solvent octane was developed. The process was conducted in air at - 90℃ to synthesize high-quality CsPbX3 NCs showing 12-44 nm wide emission and high photoluminescence quantum yield, exceeding 90%. An in situ anion-exchange method was developed to tune CsPbX3 NC photoluminescence emission, using PbX2 dissolved in octane as the halide source. NC morphology was controlled by dissolving specific metal-organic salts in the precursor solution prior to nucleation, and nanocubes, nanodots, nanosheets, nanoplatelets, nanorods, and nanowires were obtained following the same general method providing a facile, versatile route to controlling CsPbX3 NC emission bands and morphologies, which will broaden the range of CsPbX3 NC practical applications.展开更多
All-inorganic CsPbX3(X = I, Br) perovskites without organic component are promising for long-term stability but face main challenges of facile fabrication and phase stability. Here we discover a general organic methyl...All-inorganic CsPbX3(X = I, Br) perovskites without organic component are promising for long-term stability but face main challenges of facile fabrication and phase stability. Here we discover a general organic methylamine acetate salt mediated growth method to deposit high quality phase pure and stable CsPbX3(X = I, Br) perovskite films via a novel precursor consisting of stoichiometric cesium acetate(CsAc),methylamine halide(MAX) and lead halide(PbX2). Interestingly, these organic salts of CsAc and MAX could efficiently promote the crystallization process especially lower the crystallization temperature,but do not introduce the incorporation of organic MA cation into all-inorganic CsPbX3 perovskites.These phase pure and stable CsPbX3 perovskites with tunable band gaps can be fabricated into high efficiency photovoltaics. Our organic salt mediated growth of all-inorganic perovskite not only reveals the all-inorganic CsPbX3 perovskite’s unique crystal growth mechanism but also demonstrates their promising application for photovoltaics.展开更多
Currently,lead halide perovskite quantum dots(PeQDs)have attracted great attention due to their spectacular photophysical properties.However,the toxicity of Pb2+heavy metal ions in CsPbX3 PeQDs limits their practical ...Currently,lead halide perovskite quantum dots(PeQDs)have attracted great attention due to their spectacular photophysical properties.However,the toxicity of Pb2+heavy metal ions in CsPbX3 PeQDs limits their practical applications.Herein,a facile post-treatment doping method is proposed,which enables the preparation of highly luminescent low-toxic CsPbX3:Mn^2+PeQDs from nonluminescent Cs4PbX6 PeQDs at water interface.The monodispersed CsPbX3:Mn^2+PeQDs exhibit excellent photophysical properties,including high photoluminescence quantum yield up to 87%.The reaction process and doping mechanism are deeply explored through in-situ monitoring.By simply adjusting the halide composition of the original Cs4PbX6 PeQDs or Mn doping concentration,a series of CsPbX3:Mn^2+PeQDs with adjustable emission could be obtained.Further,the CsPbX3:Mn^2+Q-LED was fabricated and exhibited excellent orange light with the color coordinates of(0.564,0.399),correlated color temperature(CCT)of 1,918 K,and luminous efficiency(LE)of 24 lm/W,which illustrate the great promise in light emitting diode(LED)applications.This work not only provides a facile method for the preparation of highly luminescent low-toxic CsPbX3:Mn^2+PeQDs,but also provides insights into the mechanism of doping process.展开更多
All-inorganic perovskite CsPbX_(3)(X=Cl,Br,I)nanocrystals(NCs)have emerged as promising candidates for light-emitting diode(LED)displays due to their outstanding photophysical properties.However,their practical applic...All-inorganic perovskite CsPbX_(3)(X=Cl,Br,I)nanocrystals(NCs)have emerged as promising candidates for light-emitting diode(LED)displays due to their outstanding photophysical properties.However,their practical application remains hindered by poor stability and the inherent toxicity of Pb2+.In this study,we present a two-step heating method to synthesize CsPb_(1-x)Zn_(x)Br_(3)NCs with enhanced optoelectronic performance and uniform dispersion.The optimized Zn^(2+)-doped NCs achieve a photoluminescence quantum yield(PLQY)of 86%,with a reduction in lattice spacing from 0.384 to 0.365 nm,attributed to increased perovskite lattice formation energy and effective surface passivation.To further improve stability,a silica(SiO_(2))shell is introduced via surface modification with(3-aminopropyl)triethoxysilane(APTES),forming CsPb_(0.7)Zn_(0.3)Br_(3)@SiO_(2)core–shell NCs.At an optimal APTES/B-site metal ion molar ratio of 1.8,the PLQY increases to 96%.The SiO2encapsulation significantly enhances environmental stability,with coated NCs retaining 43%of their initial photoluminescence(PL)intensity after immersion in water for 36 h,compared to only 5%for uncoated NCs.Furthermore,after ethanol treatment for 210 min,the coated NCs retain 39%of their initial PL intensity,while the uncoated counterparts retain merely7%.The enhanced stability and luminescence performance of CsPb_(0.7)Zn_(0.3)Br_(3)@SiO_(2)NCs make them highly promising for LED applications.White light-emitting diodes(WLEDs)fabricated using these NCs exhibit a color rendering index(CRI)of 78.2,a correlated color temperature(CCT)of 5470 K,and a luminous efficiency(LE)of 54.2 lm/W,demonstrating significant potential for next-generation display and lighting technologies.展开更多
Femtosecond laser(fs)irradiation is an effective way to print perovskite quantum dots(PeQDs)in robust glass.Nevertheless,the laser writing-erasing-recovery process of PeQDs is highly dependent on the glass network str...Femtosecond laser(fs)irradiation is an effective way to print perovskite quantum dots(PeQDs)in robust glass.Nevertheless,the laser writing-erasing-recovery process of PeQDs is highly dependent on the glass network structure,which is far from being well understood.In this work,we demonstrate that the lanthanide oxides(Ln_(2)O_(3),Ln=La,Gd and Lu)in borosilicate glass enable to modulate the connectivity of the silicon-oxygen network and control in situ formation of CsPbBr_(3)PeQDs induced by fs laser.Importantly,PeQDs can be erased in specific regions through subsequent laser irradiation only when doped with an optimal concentration of Ln_(2)O_(3),which facilitates a looser network structure and reduces the crystallization barrier for ion migration.Subsequently,the degraded perovskite material can autonomously regenerate due to the water molecule invasion.The recovery time shows significant variation determined by the type and concentration of lanthanide ions.This reversible luminescence can be cycled multiple times while maintaining stable luminescence properties,providing a foundation for the development of innovative encryption methods in safeguarding information and anti-counterfeiting.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11474018,61704007,and 61575019)the National Key Research and Development Program of China(Grant No.2017YFB0404501)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.2017RC034)the Shenzhen China Star Optoelectronics Technology Co.,Ltd
文摘Inorganic lead halide perovskite nanocrystals(NCs)with superior photoelectric properties are expected to have excellent performance in many fields.However,the anion exchange changes their features and is unfavorable for their applications in many fields.Hence,impeding anion exchange is important for improving the composition stability of inorganic lead halide perovskite NCs.Herein,CsPb X3(X=Cl,Br)NCs are coated with Cs4PbX6 shell to impede anion exchange and reduce anion mobility.The Cs4PbX6 shell is facily fabricated on CsPbX3 NCs through high temperature injection method.Anion exchange experiments demonstrate that the Cs4 PbX6 shell completely encapsulates CsPbX3 NCs and greatly improves the composition stability of CsPbX3 NCs.Moreover,our work also sheds light on the potential design approaches of various heterostructures to expand the application of CsPbM3(M=Cl,Br,I)NCs.
文摘Halide perovskite （CsPbX3, X = C1, Br, or I） quantum dots have received increasing attention as novel colloidal nanocrystals （NCs）. Accurate control of emission bands and NC morphologies are vital prerequisites for most CsPbX3 NC practical applications. Therefore, a facile method of synthesizing CsPbX3 （X = C1, Br, or I） NCs in the nonpolar solvent octane was developed. The process was conducted in air at - 90℃ to synthesize high-quality CsPbX3 NCs showing 12-44 nm wide emission and high photoluminescence quantum yield, exceeding 90%. An in situ anion-exchange method was developed to tune CsPbX3 NC photoluminescence emission, using PbX2 dissolved in octane as the halide source. NC morphology was controlled by dissolving specific metal-organic salts in the precursor solution prior to nucleation, and nanocubes, nanodots, nanosheets, nanoplatelets, nanorods, and nanowires were obtained following the same general method providing a facile, versatile route to controlling CsPbX3 NC emission bands and morphologies, which will broaden the range of CsPbX3 NC practical applications.
基金support of the National Natural Science Foundation of China (21777096, 51861145101)Huoyingdong Grant (151046)+1 种基金the support of the Initiative Postdocs Supporting Program (BX20180185)China Postdoctoral Science Foundation (2018M640387)
文摘All-inorganic CsPbX3(X = I, Br) perovskites without organic component are promising for long-term stability but face main challenges of facile fabrication and phase stability. Here we discover a general organic methylamine acetate salt mediated growth method to deposit high quality phase pure and stable CsPbX3(X = I, Br) perovskite films via a novel precursor consisting of stoichiometric cesium acetate(CsAc),methylamine halide(MAX) and lead halide(PbX2). Interestingly, these organic salts of CsAc and MAX could efficiently promote the crystallization process especially lower the crystallization temperature,but do not introduce the incorporation of organic MA cation into all-inorganic CsPbX3 perovskites.These phase pure and stable CsPbX3 perovskites with tunable band gaps can be fabricated into high efficiency photovoltaics. Our organic salt mediated growth of all-inorganic perovskite not only reveals the all-inorganic CsPbX3 perovskite’s unique crystal growth mechanism but also demonstrates their promising application for photovoltaics.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(No.U1905213).
文摘Currently,lead halide perovskite quantum dots(PeQDs)have attracted great attention due to their spectacular photophysical properties.However,the toxicity of Pb2+heavy metal ions in CsPbX3 PeQDs limits their practical applications.Herein,a facile post-treatment doping method is proposed,which enables the preparation of highly luminescent low-toxic CsPbX3:Mn^2+PeQDs from nonluminescent Cs4PbX6 PeQDs at water interface.The monodispersed CsPbX3:Mn^2+PeQDs exhibit excellent photophysical properties,including high photoluminescence quantum yield up to 87%.The reaction process and doping mechanism are deeply explored through in-situ monitoring.By simply adjusting the halide composition of the original Cs4PbX6 PeQDs or Mn doping concentration,a series of CsPbX3:Mn^2+PeQDs with adjustable emission could be obtained.Further,the CsPbX3:Mn^2+Q-LED was fabricated and exhibited excellent orange light with the color coordinates of(0.564,0.399),correlated color temperature(CCT)of 1,918 K,and luminous efficiency(LE)of 24 lm/W,which illustrate the great promise in light emitting diode(LED)applications.This work not only provides a facile method for the preparation of highly luminescent low-toxic CsPbX3:Mn^2+PeQDs,but also provides insights into the mechanism of doping process.
基金supported by the National Natural Science Foundation of China(No.52062019)the Natural Science Research Project of Higher Education Institutions in Jiangsu Province,China(No.24KJA430013)the Natural Science Foundation of Jiangsu Province for Youths,China(No.BK20230662)。
文摘All-inorganic perovskite CsPbX_(3)(X=Cl,Br,I)nanocrystals(NCs)have emerged as promising candidates for light-emitting diode(LED)displays due to their outstanding photophysical properties.However,their practical application remains hindered by poor stability and the inherent toxicity of Pb2+.In this study,we present a two-step heating method to synthesize CsPb_(1-x)Zn_(x)Br_(3)NCs with enhanced optoelectronic performance and uniform dispersion.The optimized Zn^(2+)-doped NCs achieve a photoluminescence quantum yield(PLQY)of 86%,with a reduction in lattice spacing from 0.384 to 0.365 nm,attributed to increased perovskite lattice formation energy and effective surface passivation.To further improve stability,a silica(SiO_(2))shell is introduced via surface modification with(3-aminopropyl)triethoxysilane(APTES),forming CsPb_(0.7)Zn_(0.3)Br_(3)@SiO_(2)core–shell NCs.At an optimal APTES/B-site metal ion molar ratio of 1.8,the PLQY increases to 96%.The SiO2encapsulation significantly enhances environmental stability,with coated NCs retaining 43%of their initial photoluminescence(PL)intensity after immersion in water for 36 h,compared to only 5%for uncoated NCs.Furthermore,after ethanol treatment for 210 min,the coated NCs retain 39%of their initial PL intensity,while the uncoated counterparts retain merely7%.The enhanced stability and luminescence performance of CsPb_(0.7)Zn_(0.3)Br_(3)@SiO_(2)NCs make them highly promising for LED applications.White light-emitting diodes(WLEDs)fabricated using these NCs exhibit a color rendering index(CRI)of 78.2,a correlated color temperature(CCT)of 5470 K,and a luminous efficiency(LE)of 54.2 lm/W,demonstrating significant potential for next-generation display and lighting technologies.
基金supported by the National Natural Science Foundation of China(52272141,51972060)Natural Science Foundation of Fujian Province(2024J02014,2021J01190).
文摘Femtosecond laser(fs)irradiation is an effective way to print perovskite quantum dots(PeQDs)in robust glass.Nevertheless,the laser writing-erasing-recovery process of PeQDs is highly dependent on the glass network structure,which is far from being well understood.In this work,we demonstrate that the lanthanide oxides(Ln_(2)O_(3),Ln=La,Gd and Lu)in borosilicate glass enable to modulate the connectivity of the silicon-oxygen network and control in situ formation of CsPbBr_(3)PeQDs induced by fs laser.Importantly,PeQDs can be erased in specific regions through subsequent laser irradiation only when doped with an optimal concentration of Ln_(2)O_(3),which facilitates a looser network structure and reduces the crystallization barrier for ion migration.Subsequently,the degraded perovskite material can autonomously regenerate due to the water molecule invasion.The recovery time shows significant variation determined by the type and concentration of lanthanide ions.This reversible luminescence can be cycled multiple times while maintaining stable luminescence properties,providing a foundation for the development of innovative encryption methods in safeguarding information and anti-counterfeiting.
