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采用超高真空化学气相淀积系统制备了小尺寸、高密度、纵向自对准的Ge量子点 .通过TEM和AFM对埋层和上层量子点的形貌和尺寸分布进行了研究 ,对生长的温度和时间进行了优化 .采用硼预淀积的方法得到了尺寸分布小于 3 %的均匀的圆顶形Ge量子点 .采用低温光荧光测量了多层量子点的光学特性 .在 10K的PL谱可以观察到明显的蓝移现象 ,表明量子点中较强的量子限制效应 .量子点非声子峰的半高宽约为 46meV ,表明采用UHV/CVD工艺生长的多层量子点具有较窄的尺寸分布 .
The ultra-high vacuum chemical vapor deposition system was used to prepare Ge quantum dots of small size, high density and vertical self-alignment.The morphology and size distribution of the buried and upper quantum dots were studied by TEM and AFM, Temperature and time were optimized.The uniform dome-shaped Ge quantum dots with size distribution of less than 3% were obtained by boron pre-deposition method.The optical properties of multilayer QDs were measured by low-temperature photoluminescence A clear blue-shift phenomenon can be observed, indicating a strong quantum confinement effect in quantum dots.The FWHM of the non-phonon quantum dots is about 46 meV, indicating that the multilayer quantum dots grown by the UHV / CVD process have narrower Size distribution.