ZnO quantum dots embedded in a SiO2 nanoparticle layer grown by atomic layer deposition

We have fabricated ZnO quantum dots embedded in an amorphous silicon oxide layer by atomic layer deposition (ALD). SiO2 nanoparticles with diameters of approximately 10 nm dispersed in isopropyl alcohol solution were spin-on coated on the Si substrate and dried in an oven. Subsequently, ALD of ZnO was performed using two precursors, Zn(C2H5)(2) and H2O, which can infiltrate into the small voids between SiO2 nanoparticles. It is revealed that the deposited ZnO was uniformly embedded in the SiO2 layer as crystalline ZnO quantum dots with diameters in the range of about 3-8 nm after a high-temperature post-deposition annealing treatment. The quantum confinement effect of the ZnO dots is well manifested by a significant blue-shift of about 80 meV in the photoluminescence spectrum at room temperature. This technique is applicable to a new fabrication route of optoelectronic devices such as UV light emitting diodes and lasers. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim