Method of preparing light-emitting porous silicon from LiAlH4

Abstract

A method of preparing light-emitting porous silicon from LiAlH4 comprises the steps of uniformly mixing white carbon black and LiAlH4 at a weight part ratio of (0.8-1.6):(0.53-1.13) to form a mixture, and putting the mixture in a heating furnace with the furnace chamber volume of 10-30L; uniformly spreading 100-325-mesh carbon powder on the surface of the mixture at a weight part ratio of the powdered carbon to the mixture of (0.07-0.17):(1.33-2.73); raising the temperature of a furnace chamber of the heating furnace to 400-550 DEG C within 1-5h, and keeping the temperature for reaction for 3-5h to form a reaction product; gradually cooling the reaction product to the room temperature at a rate of 55-65 DEG C per hour, washing the reaction product with hydrochloric acid, room temperature distilled water and alcohol sequentially for at least once to obtain a washing product, and drying the washing product for 2-3h at 90-110 DEG C to form the light-emitting porous silicon with a better photoelectric effect.

Description

technical field [0001] The present invention relates to a kind of using LiAlH 4 A method for preparing luminescent porous silicon. Background technique [0002] Most of the existing methods for preparing luminescent porous silicon adopt electrochemical corrosion method, that is, in a polytetrafluoroethylene corrosion tank, insert a silicon wafer and a platinum wafer as the anode and cathode respectively, and use hydrofluoric acid or hydrofluoric acid plus ethanol As an electrolyte, the preparation of luminescent porous silicon is limited by many factors such as the concentration and composition of the solution, current density, resistivity, environmental protection and temperature, and the preparation of luminescent porous silicon is more sensitive to light. The chemical reaction process of preparing luminescent porous silicon by this method is complicated and not completely clear up to now. In hydrofluoric acid solution, the electrochemical corrosion rate of silicon wafer ...

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Problems solved by technology

[0002] Most of the existing methods for preparing luminescent porous silicon adopt electrochemical corrosion method, that is, in a polytetrafluoroethylene corrosion tank, insert a silicon wafer and a platinum wafer as the anode and cathode respectively, and use hydrofluoric acid or hydrofluoric acid plus ethanol As an electrolyte, the preparation of luminescent porous silicon is limited by many factors such as the concentration and composition of the solution, current density, resistivity, environmental protection and temperature, and the preparation of luminescent porous silicon is more sensitive to light.

The chemical reaction process of preparing luminescent porous silicon by this method is complicated, and it is not completely clear so far. In the hydrofluoric acid solution, the electrochemical corrosion rate of silicon wafers is extremely slow, and the waste liquid produced is also difficult to handle.

[0003] This method has the following deficiencies: 1. Waste liquid, etc. are generated during the preparation process, which pollutes the environment; 2. A large amount of electric energy is consumed during the preparation process, resulting in high energy consumption; 3. It is difficult to purify the prepared luminescent porous silicon; 4. The production cost is high (the price of raw materials is high), the equipment used must be corrosion-resistant (hydrofluoric acid is extremely corrosive), and the structure is relatively complicated

The above-mentioned lack of stuffing makes it difficult for the existing methods for preparing luminescent porous silicon to be used on a large scale in industry

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