Abstract: A family of discrete and uniformly sized silicon nanoparticles, including 1 (blue emitting), 1.67 (green emitting), 2.15 (yellow emitting), 2.9 (red emitting) and 3.7 nm (infrared emitting) nanoparticles, and a method that produces the family. The nanoparticles produced by the method of the invention are highly uniform in size. A very small percentage of significantly larger particles are produced, and such larger particles are easily filtered out. The method for producing the silicon nanoparticles of the invention utilizes a gradual advancing electrochemical etch of bulk silicon, e.g., a silicon wafer. The etch is conducted with use of an appropriate intermediate or low etch current density. An optimal current density for producing the family is ˜10 milli Ampere per square centimeter (10 mA/cm2). Higher current density favors 1 nm particles, and lower the larger particles.

Abstract: According to the invention, silicon nanoparticles are applied to a substrate using an electrochemical plating processes, analogous to metal plating. An electrolysis tank of an aqueous or non-aqueous solution, such as alcohol, ether, or other solvents in which the particles are dissolved operates at a current flow between the electrodes. In applying silicon nanoparticles to a silicon, metal, or non-conducting substrate, a selective area plating may be accomplished by defining areas of different conductivity on the substrate. Silicon nanoparticle composite platings and stacked alternating material platings are also possible. The addition of metal ions into the silicon nanoparticle solution produces a composite material plating. Either composite silicon nanoparticle platings or pure silicon nanoparticle platings may be stacked with each other or with convention metal platings.

Abstract: According to the invention, silicon nanoparticles are applied to a substrate using an electrochemical plating processes, analogous to metal plating. An electrolysis tank of an aqueous or non-aqueous solution, such as alcohol, ether, or other solvents in which the particles are dissolved operates at a current flow between the electrodes. In applying silicon nanoparticles to a silicon, metal, or non-conducting substrate, a selective area plating may be accomplished by defining areas of different conductivity on the substrate. Silicon nanoparticle composite platings and stacked alternating material platings are also possible. The addition of metal ions into the silicon nanoparticle solution produces a composite material plating. Either composite silicon nanoparticle platings or pure silicon nanoparticle platings may be stacked with each other or with convention metal platings.

Abstract: Harmonic incident radiation is obtained from a silicon nanoparticle microcrystal or microcrystal film. The preferred film comprises silicon nanoparticles, dimensioned on the order of one nanometer, reconstituted into a device quality crystalline film. The microcrystal film emits the second harmonic of incident radiation for excitations in the range of about 600-1000 nm. A preferred device according to the invention includes a silicon nanoparticle microcrystal film formed on a substrate, such as silicon or glass. Crystals of the silicon nanoparticles, due to the harmonic response, also demonstrate the capability to serve as piezoelectric material and as an improved biological marker. Since the emission response of the silicon nanoparticle crystals will be influenced by surrounding electric fields, the microcrystals also provide for electrochromatic mapping of electric field distribution in general and in electronic devices.

Abstract: A family of discrete and uniformly sized silicon nanoparticles, including 1 (blue emitting), 1.67 (green emitting), 2.15 (yellow emitting), 2.9 (red emitting) and 3.7 nm (infrared emitting) nanoparticles, and a method that produces the family. The nanoparticles produced by the method of the invention are highly uniform in size. A very small percentage of significantly larger particles are produced, and such larger particles are easily filtered out. The method for producing the silicon nanoparticles of the invention utilizes a gradual advancing electrochemical etch of bulk silicon, e.g., a silicon wafer. The etch is conducted with use of an appropriate intermediate or low etch current density. An optimal current density for producing the family is ˜10 milli Ampere per square centimeter (10 mA/cm2). Higher current density favors 1 nm particles, and lower the larger particles.