Traditional Incandescent Bulbs:
* Filament: Tungsten (for its high melting point and resistance)
* Base: Brass or aluminum
* Lead-in wires: Nickel-plated copper or iron
* Support wires: Nickel-chromium alloys
LED Bulbs:
* LED chip: Semiconductors like gallium nitride or aluminum gallium indium phosphide
* Base: Brass, aluminum, or plastic
* Lead-in wires: Copper
* Heat sink: Aluminum or copper (for dissipating heat)
Fluorescent Bulbs:
* Electrodes: Tungsten with a small amount of thorium
* Mercury vapor: Mercury
* Glass tube: Borosilicate glass (with a phosphor coating on the inside)
* Base: Brass, aluminum, or plastic
Halogen Bulbs:
* Filament: Tungsten (with a small amount of halogen gas like iodine or bromine)
* Glass bulb: Quartz glass (for high temperatures)
* Base: Brass or aluminum
* Lead-in wires: Nickel-plated copper
The specific metals used in each type of bulb can vary slightly depending on the manufacturer.
