Abstract: A method for improving internal quantum efficiency of a group-III nitride-based light emitting device is disclosed. The method includes the steps of: providing a group-III nitride-based substrate having a single crystalline structure; forming on the group-III nitride-based substrate an oxide layer, having a plurality of particles, without absorption of visible light, size, shape, and density of the particles are controlled by reaction concentration ratio of nitrogen/hydrogen, reaction time and reaction temperature; and growing a group-III nitride-based layer over the oxide layer; wherein the oxide layer prevents threading dislocation of the group-III nitride-based substrate from propagating into the group-III nitride-based layer, thereby improving internal quantum efficiency of the group-III nitride-based light emitting device.

Abstract: A method for improving light extraction efficiency of a group-III nitride-based light emitting device is disclosed. The method includes the steps of: providing a group-III nitride-based light emitting device having a top surface; disposing a seed layer on the top surface for increasing adhesion of the group-III nitride-based light emitting device; and forming a patterned oxide layer, having a plurality of nanostructure particles, without absorption of visible light on the seed layer. The size and shape of the nanostructure particles are controlled by reaction concentration, time and temperature during the patterned oxide layer formation, thereby improving light extraction efficiency of the group-III nitride-based light emitting device without damaging the group-III nitride-based light emitting device.

Abstract: A method of forming a vertical structure light emitting diode with a heat exhaustion structure, comprising the steps of: providing a sapphire substrate; producing a number of recesses on the sapphire substrate, each of which has a depth of p; forming a buffer layer having a number of protrusions, each of which has a height of q smaller than p so that when the protrusions of the buffer layer are accommodated within the recesses of the sapphire substrate, a number of gaps are formed therebetween for heat exhaustion; growing a number of luminescent layers on the buffer layer, having a medium layer formed between the luminescent layers and the buffer layer; etching through the luminescent layers and the buffer layer to form a duct for heat exhaustion; removing the sapphire substrate by excimer laser lift-off (LLO); roughening the medium layer; and depositing electrodes on the roughened medium layer.

Abstract: The present invention relates to a method for treating spent tin or tin/lead stripping solution used in the electronic industry, particularly in the manufacture of printed circuit boards or a lead frames. Said method comprises (i) electrolytically reducing copper ions in the solution to copper at a low temperature; (ii) electrolytically oxidizing Sn2+ and Pb2+ in the solution at a high temperature to form solid tin and lead oxides and hydroxides; (iii) separating solid tin and lead oxides and hydroxides from the solution; (iv) dissolving tin and lead oxides and hydroxides obtained in step (iii) in a strong alkali or acidic solution; and (v) electrolytically reducing the alkali or acidic solution obtained in step (iv) at a high temperature to recover metallic tin and lead. Also, the filtrate obtained in step (iii) above is useful for preparing fresh tin or tin/lead stripping solution.

Abstract: The present invention relates to a method for treating spent tin or tin/lead stripping solution used in the electronic industry, particularly in the manufacture of printed circuit boards or a lead frames. Said method comprises (i) electrolytically reducing copper ions in the solution to copper at a low temperature; (ii) electrolytically oxidizing Sn2+ and Pb2+ in the solution at a high temperature to form solid tin and lead oxides and hydroxides; (iii) separating solid tin and lead oxides and hydroxides from the solution; (iv) dissolving tin and lead oxides and hydroxides obtained in step (iii) in a strong alkali or acidic solution; and (v) electrolytically reducing the alkali or acidic solution obtained in step (iv) at a high temperature to recover metallic tin and lead. Also, the filtrate obtained in step (iii) above is useful for preparing fresh tin or tin/lead stripping solution.