Temperature-dependent Photoluminescence Of Rare Earth Ions Doped All-inorganic Perovskite Quantum Dots

Perovskite quantum dots(QDs)have been widely studied as promising optoelectronic materials and have great potential application in the fields of illumination,display,photoelectric detection,solar cells and laser due to their excellent optical properties,which including the large absorption across section,narrow band,high fluorescence quantum efficiency,and tunable luminescence from ultraviolet to infrared region by controlling halogen components and particle size.QDs are new temperature sensitive materials,but the corresponding researches focus on ?-? colloidal semiconductor QDs.Because of their ionic crystal structure,perovskite QDs are more sensitive to temperature than IV-VI QDs.In this paper,all inorganic perovskite QDs were prepared by thermal injection method,the temperature sensitive properties of all inorganic perovskite CsPbCl3 QDs were studied.The rare earth doped QDs materials with multi-mode emission are realized by adding rare earth ions to QDs.The accuracy and stability of the temperature measurement of the QDs are enhanced by using the fluorescence intensity ratio(FIR)between the luminescence peak of the QDs and the luminescent peaks of the rare earth ions.The main researches are as follows:(1)The Temperature-dependent photoluminescence(PL)spectra of all inorganic perovskite CsPbCl3 QDs were measured to study their PL properties in the range of 22-62 ?.With the increase of temperature,the CsPbCl3 QDs showed a good temperature sensitive characteristic,the peak wavelength was gradually shifted to the long wave section,the full width of half maximum(FWHM)was gradually broaden,and the PL intensities of the exciton emission peak decreased rapidly.The results show that the PL intensities is more sensitive to the temperature change,and the peak position and the FWHM have a good linear relationship with the temperature.(2)The temperature sensitive properties of Ce3+ doped CsPbCl3 QDs were studied.The temperature dependence spectra of CsPbCl3 QDs and CsPbCl3:Ce3+ QDs were compared.With the temperature increasing,both the PL intensities of host QDs and Ce3+,but the reduced degrees are different.The emission of host QDs decreased sharply with temperature increasing while the emission of Ce3+ decreased slowly.The maximal values of absolute and relative sensitivities of CsPbCl3:Ce3+ QDs were obtained through calculating the FIR between the emission intensities of CsPbCl3 QDs and Ce3+,the results indicated that CsPbCl3:Ce3+ QDs have great potentialities as a luminescent thermometer.(3)The PL properties of Eu3+ doped CsPbCl3 and CsPbBr3 QDs are investigated.The results show that the luminescence intensity of CsPbX3(X=Cl,Br)QDs host decreases with the increase of temperature,while the luminescence intensity of Eu3+remains unchanged.The FIR between the CsPbBr3 QDs and the 5D0 to 7F2 transition luminescence peaks of Eu3+ is calculated,and the absolute sensitivity and relative sensitivity of the CsPbBr3:Eu3+ QDs are obtained.