Study of Self-Organized CdS Q-Dots

Abstract

Self-organized cadmium sulfide quantum dots assembled using wet synthesis route on glass/ITO as well as Si(100) substrates have been investigated, using X-ray diffraction and transmission electron microscopy. The quantum dots have been shown to grow with a strong (111) orientation with narrow size distribution. Self-organized growth of the quantum dots was examined by high resolution imaging with an atomic force microscope. It is shown that increased self-organization is obtained on silicon substrate. The role of surfactant in imparting self-organization has been invoked to explain the observed morphological features. The as grown Q-dots exhibited size dependent blue shift in the absorption edge. The luminescence behavior of the quantum dots self-organized on glass/ITO as well as Si(100) substrate has also been examined. It is shown that substantial enhancement in luminescence yield is obtained for quantum dots grown on silicon substrate. A model to explain the observed luminescence enhancement has also been presented.