The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential...The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential applications in sensor,energy harvesting and solar cells.However,the CT and ET between them are not clear.Herein,we examine the ET in a(PEA)_(2)PbI_(4)/WS_(2)(PEA stands for phenethylamine and(PEA)_(2)PbI_(4)is abbreviated as PEPI)heterojunction using combined ultrafast spectroscopy and nonlinear optical absorption measurements.The ET from PEPI to WS_(2)predicted by band alignment is first observed with photoluminescence spectroscopy and then revealed by femtosecond transient absorption spectroscopy to exhibit a high ET efficiency approximating 68%.展开更多
The spectral phase of the femtosecond laser field is an important parameter that affects the up-conversion(UC)luminescence efficiency of dopant lanthanide ions.In this work,we report an experi-mental study on controll...The spectral phase of the femtosecond laser field is an important parameter that affects the up-conversion(UC)luminescence efficiency of dopant lanthanide ions.In this work,we report an experi-mental study on controlling the UC lmiiinescence efficiency in Sm^3+:NaYF4 glass by 800-nm femtosec-ond laser pulse shaping using spectral phase modulation.The optimal phase control strategy efficiently enhances or suppresses the UC luminescence intensity.Based on the laser-power dependence of the UC luminescence intensity and its comparison with the luminescence spectrum under direct 266-nm fem-tosecond lciser irradiation,we propose herein an excitation model combining non-resonant two-photon absorption with resonance-media ted three-photon absorption to explain the experimental observations.展开更多
Tuning the color output of rare-earth ion doped luminescent nanomaterials has important scientific significance for further extending applications in color displays, laser sources, optoelectronic devices, and biolabel...Tuning the color output of rare-earth ion doped luminescent nanomaterials has important scientific significance for further extending applications in color displays, laser sources, optoelectronic devices, and biolabeling. In previous studies, pre-designed phase modulation of the femtosecond laser field has been proven to be effective in tuning the luminescence of doped rare-earth ions. Owing to the complex light–matter interaction in the actual experiment, the dynamic range and optimal efficiency for color tuning cannot be determined with the pre-designed phase modulation. This article shares the development of an adaptive femtosecond pulse shaping method based on a genetic algorithm, and its use to manipulate the green and red luminescence tuning in an Er3+-doped glass ceramic under 800-nm femtosecond laser field excitation for the first time. Experimental results show that the intensity ratio of the green and red UC luminescence of the doped Er3+ ions can be either increased or decreased conveniently by the phase-shaped femtosecond laser field with an optimal feedback control. The physical control mechanisms for the color tuning are also explained in detail. This article demonstrates the potential applications of the adaptive femtosecond pulse shaping technique in controlling the color output of doped rare-earth ions.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52472153,11704081,and 62175210)Guangxi Natural Science Foundation(No.2020GXNSFAA297182)the special fund for"Guangxi Bagui Scholars,"National Science and Technology Innovation Talent Cultivation Program(No.2023BZRC016)
文摘The interactions of charge transfer(CT)and nonradiative energy transfer(ET)in heterojunctions of two-dimensional(2D)transition metal dichalcogenides and quasi-2D single crystal perovskite thin films have the potential applications in sensor,energy harvesting and solar cells.However,the CT and ET between them are not clear.Herein,we examine the ET in a(PEA)_(2)PbI_(4)/WS_(2)(PEA stands for phenethylamine and(PEA)_(2)PbI_(4)is abbreviated as PEPI)heterojunction using combined ultrafast spectroscopy and nonlinear optical absorption measurements.The ET from PEPI to WS_(2)predicted by band alignment is first observed with photoluminescence spectroscopy and then revealed by femtosecond transient absorption spectroscopy to exhibit a high ET efficiency approximating 68%.
基金the Na-tional Natural Science Foundation of China(Grant Nos.91850202,11774094,11727810,11804097,and 61720106009)the Science and Technology Commission of Shanghai Municipality(Grant No.17ZR146900)+1 种基金the China Postdoctoral Science Foundation(Grant No.2018M641958)ECNU Academic Innovation Promotion Program for Excellent Doctoral Students(Grant No.YBNLTS2019-011).
文摘The spectral phase of the femtosecond laser field is an important parameter that affects the up-conversion(UC)luminescence efficiency of dopant lanthanide ions.In this work,we report an experi-mental study on controlling the UC lmiiinescence efficiency in Sm^3+:NaYF4 glass by 800-nm femtosec-ond laser pulse shaping using spectral phase modulation.The optimal phase control strategy efficiently enhances or suppresses the UC luminescence intensity.Based on the laser-power dependence of the UC luminescence intensity and its comparison with the luminescence spectrum under direct 266-nm fem-tosecond lciser irradiation,we propose herein an excitation model combining non-resonant two-photon absorption with resonance-media ted three-photon absorption to explain the experimental observations.
基金Financial supports from the National Natural Science Foundation of China (Grant Nos. 11727810, 61720106009,and 11774094)Science and Technology Commission of Shanghai Municipality (Grant Nos. 17ZR146900 and 16520721200) are gratefully acknowledged.
文摘Tuning the color output of rare-earth ion doped luminescent nanomaterials has important scientific significance for further extending applications in color displays, laser sources, optoelectronic devices, and biolabeling. In previous studies, pre-designed phase modulation of the femtosecond laser field has been proven to be effective in tuning the luminescence of doped rare-earth ions. Owing to the complex light–matter interaction in the actual experiment, the dynamic range and optimal efficiency for color tuning cannot be determined with the pre-designed phase modulation. This article shares the development of an adaptive femtosecond pulse shaping method based on a genetic algorithm, and its use to manipulate the green and red luminescence tuning in an Er3+-doped glass ceramic under 800-nm femtosecond laser field excitation for the first time. Experimental results show that the intensity ratio of the green and red UC luminescence of the doped Er3+ ions can be either increased or decreased conveniently by the phase-shaped femtosecond laser field with an optimal feedback control. The physical control mechanisms for the color tuning are also explained in detail. This article demonstrates the potential applications of the adaptive femtosecond pulse shaping technique in controlling the color output of doped rare-earth ions.
