Here's how it works:
* Selenium is a photoconductor: This means its electrical conductivity increases when exposed to light.
* In photocopiers/laser printers: A selenium drum is used. It's initially charged with a uniform electrical charge.
* Image creation: When light shines on the drum, the exposed areas become conductive and lose their charge.
* Toner application: The remaining charged areas attract toner particles (a fine powder).
* Transfer to paper: The toner image is then transferred to the paper, and heat is used to fuse the toner permanently.
In summary, selenium's ability to change its conductivity in response to light is what makes it a crucial component in these copying technologies.
