SiC和CdTe量子点间荧光共振能量转移

Resonant energy transfer between SiC and CdTe quantum dots

采用水相法制备了巯基乙胺包裹的CdTe量子点,用湿化学刻蚀法制得了SiC量子点,并对CdTe和SiC量子点的光学特性进行了研究.结果表明:随着激发波长的增加,因量子限制效应,SiC量子点荧光的最大发射峰出现红移;CdTe量子点的发射谱和SiC量子点的吸收谱有较大的重叠,且带边发射有较大的能量分离;CdTe量子点和SiC量子点之间存在福斯特共振能量转移.同时,CdTe和SiC混合液蒸干后的荧光光谱显示,供体SiC的荧光减弱,而受体CdTe的荧光增强;相同大小的CdTe、SiC及CdTe和SiC混合物的液滴在空气中自然蒸发时,液滴的颜色在紫外灯照射下发生了变化,这是由于蒸发过程中,液滴体积减小,导致液滴中量子点间的距离减小,有利于CdTe量子点和SiC量子点间发生福斯特共振能量转移.

3-Mercaptopropionic acid（MPA）-capped CdTe quantum dots（QDs）were synthesized in aqueous solution.SiC QDs were performed by wet chemical etching of cubic SiC powder.The optical properties of SiC QDs exhibited that PL emission peaks shifted to long wavelength with the increase of excitation wavelength,which attributed to the quantum confinement effect.In addition,fluorescence emission spectra of SiC QDs overlapped with the absorption spectra of CdTe QDs,and there was significant energy separation between band emissions from CdTe QDs and SiC QDs.Hence,the forster resonance energy transfer between CdTe and SiC QDs was studied.PL spectra of the mixture of CdTe and SiC show that the PL intensity of SiC decreases and that of CdTe increases.In addition,the emission color of the mixture of CdTe and SiC has changed under an ultraviolet lamp at different times during evaporation of solvent.These results are due to the forster resonance energy transfer between CdTe and SiC QDs.