热处理温度对量子点粒度分布的影响

Influence of annealing temperature on the distribution of particle sizes of quantum dots doped glass

为了明确热处理温度对熔融法制备Pb Se量子点玻璃材料的影响,实验对比了核化时间、晶化温度、晶化时间对晶体大小、粒度分布和吸收光谱特性的影响.在相同核化温度、不同晶化温度条件下,各样品的透射电子显微镜图显示都有一定量的晶体形成,但其晶化程度、尺寸大小及分布有明显不同.通过计算晶体粒度分布定量地揭示出,随着晶化温度的提高,量子点晶体尺寸逐渐增大,从而提高了晶体颗粒的浓度.吸收光谱的测量也表明,随着晶化温度的升高,吸收峰从无到有不断增强且出现红移现象.而当晶化温度较低时,虽有晶体形成,但无明显吸收峰,主要是由于晶体尺寸较小,浓度较低,晶体颗粒的吸收峰被背景材料所掩盖.研究结果可为制备具有一定浓度的不同尺寸的量子点晶体,进而获得多个波段下较强的吸收和辐射的量子点玻璃提供一定的参考.

In order to understand the influence of annealing temperature on PbSe quantum dots doped glass produced by a melt-annealing technique, experiments are carried out to compare the influences of different nucleation durations, crystallization temperatures and time on the particle size, distribution and absorption spectrum. Under the condition of the same nucleation temperatures and different crystallization temperatures, the transmission electron microscope images of all samples show that a certain quantity of PbSe crystals are crystallized in the glass. While the particle sizes and densities are slightly different. The calculated distribution of the particle sizes quantitatively indicates that the particle size will be enlarged with the increase of crystallization temperature and the crystal particle density. The measured absorption spectrum shows that the peak value of absorption spectrum increases gradually with increasing the crystallization temperature. At the same time, the peak value shows a red-shift phenomenon. While under the relatively low crystallization temperature, the infrared absorption peak cannot be obtained in spite that some crystals have grown inside the glass. The absorption spectrum is covered up by the background signals because of the relatively smaller particle size and density. This work will be benefit of producing different size quantum dots with a certain density, and realizing stronger absorption and emission in multib~.nd