Light emitting diode with luminescent nanoparticles

Light emitting diode with luminescent nanoparticles

Technology description: nanoparticles or quantum dots will increase the electron density (density of state), thereby increasing the luminous efficiency of the material. The small size of the luminescent nanoparticles can be formed by chemical method, and the nano particles are uniformly dispersed in the solvent.

Methods the epitaxial substrate, the choice is very demanding, need to have the properties of quantum dots with the lattice, and its formation is very slow (such as several micrometers per hour; m/hr), very low density per unit area covered, vacuum equipment to carry out the necessary process needs.

The chemical method for the formation of luminescent nanoparticles has the following advantages: (1) can be produced in large quantities and dispersed in the solvent, in order to dissolve the liquid; (2) can be used in the coating methods such as spray, dip or spin coating. The film coating method can instantly on any substrate; (3) speed up to several microns per second (m/sec), can increase the speed of thousands of times, to form a diode with high density and large area, and the area is only limited to the area of the substrate.

We provide a process for producing high quality, narrow bandwidth light emitting devices with homogeneous sized particles of colloidal oxides, semiconductors, or polymeric luminescent nanoparticles. This process using colloidal nanoparticles luminescence can be homogeneously dispersed in the liquid, then use simple film method such as spraying, dipping, or coating nanoparticles uniformly processed in any shape, size, type of substrate, and a cheap, large area, complex, and highly efficient luminous body.

We have demonstrated the feasibility of this process with CdS colloidal nanoparticles, which show that the light-emitting diode can be coated on a silicon chip by CdS nanoparticles by spin coating method, coupled with a Cr/Au electrode. Figure two shows the green spectrum of the diode.

Key schema:

Figure 1 the structure of CdS nanoparticles fabricated on silicon chip

Figure two electroluminescence spectra of CdS nanoparticles