You can make it, with plate nitrate and reductor solution. Usually make with graphite or silver with a co.emultion like benceze or toluene.
You can make it, using pencil 2H. More graphite, less resistance. More wax(or pencil harder), more resistance.
You can make it, using graphite (printing with a pencil) and ferric hidroxide.
Other Diodes .-
- Copper oxide/copper - This consisted of copper filings; 1/2 of the filings I heated on the stove so that they got coated with copper oxide (tumed reddish), other 1/2 left shiny. Filled a small glass tube with oxide coated filings on one side and shiny filings an the other. Plugged the ends and inserted a couple pins in each end. The junction needed some manipulation periodically but it did work.
- galena/carbon rod
- graphite/copper oxide
- graphite/iron oxide. This my diode but, ink in a piece of paper.(graphite is from a pencil, and iron oxide is from a oxide metal Fe2O3).