A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting...A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting layer(WL)through radiative field coupling between the exciton emissions in the WL and the dipole field of metal islands.In this article we have proposed a new three-level model to simulate the exciton emission decay curve.In this model,assuming that the excitons in a metastable state will diffuse and be trapped by QDs,and then emit fluorescence in QDs,a stretchedlike exponential decay formula is derived as I(t)=At^(β−1)e^(−(rt)^(β)),which can describe well the long lifetime decay curve with an analytical expression of average lifetime(τ)=1/rГ(1/β+1),where G is the Gamma function.Furthermore,based on the proposed three-level model,an expression of the second-order auto-correlation function g^(2)(t)which can fit the measured g^(2)(t)curve well,is also obtained.展开更多
We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate...We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate of emission energy is up to 10 meV/GPa, demonstrating a controllable tuning of single photon emitters through pressure.Based on the distribution character of pressure coefficients as a function of wavelength, different kinds of atomic defect states should be responsible for the observed defect emissions.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301202)the National Natural Science Foundation of China(Grant Nos.61827823 and 11974342).
文摘A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting layer(WL)through radiative field coupling between the exciton emissions in the WL and the dipole field of metal islands.In this article we have proposed a new three-level model to simulate the exciton emission decay curve.In this model,assuming that the excitons in a metastable state will diffuse and be trapped by QDs,and then emit fluorescence in QDs,a stretchedlike exponential decay formula is derived as I(t)=At^(β−1)e^(−(rt)^(β)),which can describe well the long lifetime decay curve with an analytical expression of average lifetime(τ)=1/rГ(1/β+1),where G is the Gamma function.Furthermore,based on the proposed three-level model,an expression of the second-order auto-correlation function g^(2)(t)which can fit the measured g^(2)(t)curve well,is also obtained.
基金Supported by the Postdoctoral Science Foundation of China under Grant No.Y8T0111001.
文摘We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate of emission energy is up to 10 meV/GPa, demonstrating a controllable tuning of single photon emitters through pressure.Based on the distribution character of pressure coefficients as a function of wavelength, different kinds of atomic defect states should be responsible for the observed defect emissions.
