title: Design and synthesis of amorphous SiOx structures generated by Sn quantum dots: growth mechanism and luminescent origin.
abstract: SiOx structures with different diameters of a few hundreds of nanometers and/or a few micrometers are prepared using applied thermal evaporation. Subsequently, Sn quantum dot-based SiOx architectures are synthesized via the continuous steps of the carbothermal reduction of SnO2, substitution of Sn(4+) for In(3+), thermal oxidation of Si, Sn sublimation, interfacial reaction, and diffusion reaction consistent with corresponding phase equilibriums. Several crystalline and spherical-shaped Sn quantum dots with diameters between 2 and 7 nm are observed in the amorphous SiOx structures. The morphological evolution, including hollow Sn (or SnOx) sphere and wire-like, worm-like, tube-like, and flower-like SiOx, occurs stepwise on the Si substrate upon increasing the given process energies. The optical characteristics based on confocal measurements reveal the as-synthesized SiOx structures, irrespective of whether crystallinity is formed, which all have visible-range emissions originating from the numerous different-sized and -shaped Sn quantum dots permeating into the SiOx matrix. In addition, photoluminescence emissions ranging between ultraviolet and red regions are in agreement with confocal measurements. The origins of the morphology- and luminescence-controlled amorphous SiOx with Sn quantum dots are also discussed.
authors: School of Mechanical Engineering, Konkuk University, Seoul 143-701, Korea.
authors: Changhyun
authors: C
authors: Jin
authors: Seon Jae
authors: SJ
authors: Hwang
authors: Myeong Soo
authors: MS
authors: Cho
authors: Sun-Woo
authors: SW
authors: Choi
authors: Han Gil
authors: HG
authors: Na
authors: Suyoung
authors: S
authors: Park
authors: Hakyung
authors: H
authors: Jeong
authors: Youngwook
authors: Y
authors: Noh
authors: Dongjin
authors: D
authors: Lee