| The all-inorganic lead cesium halide(CsPbX3,X=Cl,Br and I)perovskite quantum dots(PQDs)have also begun to emerge in the field of photocatalysis due to their adjustable band gap and long carrier coefficient,Zn2+ions doping can improve their crystallinity,photocurrent,charge transport and photocatalytic activity.At the same time,CsPbX3PQDs are also applied to amplification spontaneous emission(ASE)and wide color gamut white light-emitting diode(WLED)fields because of their narrowband emission,high photoluminescence quantum yield(PLQY),absorption coefficient and potential optical gain and other considerable optical properties.In our study,firstly,a series of Zn2+doped CsPbCl1.5Br1.5and pure phase CsPbCl2Br1 PQDs glasses were synthesized by the technology of traditional heat quenching and in-situ crystallization;secondly,the colloidal CsPbX3 PQDs solution was synthesized by the hot injection,and the solution was encapsulated by silica aerogels(SiO2 AGs)to prepare a full spectra luminescent composite materials.We have carried on a series of measurements and characterization methods to study its structure,morphology,photoelectric characteristics,stability and applications in the field of photocatalysis,ASE and wide color gamut WLED.The main research points are as follows:(1)The Zn2+doped CsPbCl1.5Br1.5PQDs were successfully precipitated in the borosilicate glass using traditional heat quenching and in-situ crystallization technology.Through the Zn2+doping,the adjustable absorption edges(480nm?500nm)and band gap values(2.5eV?2.42eV)are realized.Compared with the hand grinding method,the ball grinding method can increase the specific surface area of the phtocatalyst from 1.31m2·g-1to 2.53m2·g-1.When the doping amount of Zn2+ions is 0.25,and ball grinding the powder for 11 hours,the best productivity of H2 can reach 290.67?mol·g-1.Due to the protection of the glass matrix,the photocatalyst exhibits good water stability and cyclic availability.After continuously driving the water splitting reaction for 100h,the maximum H2 production rate is 485.67?mol·g-1.(2)The precursor glass of CsPbCl2Br1PQDs was synthesized using traditional heat quenching and in-situ crystallization technology,and heat-treated for 10h within a temperature gradient from 440?to 530?.The glass samples exhibit typical blue emission(472nm?497nm),adjustable band gap(2.63eV?2.58eV),increased average particle size(3.75nm?6.2nm)and preferable crystallinity.The low-threshold ASE behavior of CsPbCl2Br1PQDs glass was realized by excitation of 800nm femtosecond laser at room temperature,indicating the threshold can be reduced from 1.24mJ/cm2 to 0.19mJ/cm2 as the crystallization temperature increases.(3)Synthesize colloidal CsPbX3PQDs solution by hot injection method and encapsulate it in superhydrophobic SiO2AGs to improve its stability.The PLQY of CsPbBr3@AGs can reach 71%,and the full width at half maximum(FWHM)of composite materials with blue,green and red light emission are 17,19 and 35,respectively,realizing narrow-band emission.Blue emitting CsPbCl2Br1@AGs,green emitting CsPbBr3@AGs and red emitting CsPbBr1I2@AGs are used as phosphors respectively,showing a wide color gamut that can cover 135%of the National Television System Committee(NTSC).WLED devices can be constructed by coupling CsPbBr3@AGs and CsPbBr1I2@AGs to Ga N blue chips.The LE,CCT and Ra of the constructed WLED are 14.55lm·W-1,5477 K,94.9,respectively. |
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