How to Make Your Own LED Corundum

Make the semiconductor wafer. This is the base of the LED. Mix a compound of gallium, phosphor and arsenic together, and place it in a high-pressure chamber. The pressure will "cook" the chemicals. Cover wafer with liquid boron oxide while it is still in the chamber. Insert a rod into the mixture and slowly remove it. The mixture will then form a tube of crystal, called an ingot. The crystals are corundums.

Cut the tube into slices of 2 mils thick, each. You will need sophisticated cutting equipment, a micrometer and possibly a microscope to do so.

Polish the wafers until they are smooth, and clean them thoroughly with mineral spirits and alcohol.

Grow additional layers of crystal. You can do so using a process called liquid phase epitaxy. To do this, you will need a furnace, such as the Koyo Thermal Systems horizontal furnace. Create another batch of gallium, arsenic and phosphor as in Step 1, except instead of drawing a tube through it, you will insert a dopant, which is a small concentration of crystal shavings, and simply melt it over the top of the wafer. The dopant is an impurity that will result in a lower electrical density in the top layer. The more dopant you use, the brighter the potential light emission. But if you use too much, the component may not work at all. Some trial and error may be required to hit the right mixture for your application.

Define contact points. Generally, you will need a negative and positive contact point. To create them, coat the wafer in photoresist and bake briefly at 215 degrees. Shine ultraviolet light at the areas that you do not want to become contact points. You essentially erase the photoresist. At the end of the process, the only unexposed photoresist compound left are your contact points. Wash the excess exposed photoresist away with developer. This is the same process as developing film).

Place the wafer in a vacuum-sealed furnace, along with a piece of conductive metal, such as led or gold. Heat the furnace until the metal turns into vapor. The vapor will coat the photoresist, forming contact points.

Heat the assembly in a furnace for several hours, at a temperature of 400 degrees or higher. Ideally, you will pump an inert gas, such as neon or argon, through the furnace. This will fuse the metal and the crystal structures together. The wiring, then, goes directly into the crystals and becomes chemically fused with them.

Mount the LED. Solder the underside of the LED, with the contact points, to the positive lead in the circuit. Connect a tiny gold lead to the negative circuit, adjacent to the LED. Using a needle, firmly press the gold wire directly against the top of the LED. The gold is soft and will distort itself and get caught up in the crystal structure of the corundum of the LED.

Encase the assembly in glass or plastic, with the two leads running inside the LED from the bottom.