title: Brightly photoluminescent phosphor materials based on silicon quantum dots with oxide shell passivation.
abstract: We demonstrate silicon-based phosphor materials which exhibit bright photoluminescence from near-infra-red to green. The colloidal composites which are composed of silicon quantum dots (SiQDs) attached on micro-size silicon particles are synthesized by electrochemical etching of silicon wafers and then dispersed in ethanol. Subsequently, isotropic etching by HF/HNO3 mixture controls the size so as the emission wavelength of SiQDs, and forms an oxide passivating shell. The phosphors can further react with alkoxysilanes to form a stable suspension in non-polar solvents for solution-processing. The resulting red-light-emitting SiQD-based phosphors in chloroform exhibit photoluminescence external quantum efficiency of 15.9%. Their thin films can be efficiently excited by InGaN light-emitting diodes and are stable in room condition.
authors.affiliation: Department of Materials Science & Engineering, University of Washington, Seattle, Washington 98195, USA.
authors.forename: Chang-Ching
authors.initials: CC
authors.lastname: Tu
authors.forename: Qifeng
authors.initials: Q
authors.lastname: Zhang
authors.forename: Lih Y
authors.initials: LY
authors.lastname: Lin
authors.forename: Guozhong
authors.initials: G
authors.lastname: Cao
mesh_terms: D008029:Lighting / Q000379:methods*; D008163:Luminescent Measurements / Q000379:methods*; D010087:Oxides / Q000737:chemistry*; D045663:Quantum Dots; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D010087:Oxides; D012822:Silicon Dioxide