Charged insulator with electrons throughout its volume?

[jcap]

Could one make a negatively-charged insulator with the extra electrons trapped all the way through its volume by building it up layer by layer with electrons "sprayed" onto each layer as it was constructed?

I guess the electrons would be trapped in empty atomic orbitals within the material - is this true?

If the electron density was too high could such a material be mechanically unstable due to the electrostatic forces within it or would the electrons somehow just quantum-mechanically tunnel out of the insulator?

 

[mfb]

Insulators won’t keep that charge long. They don’t conduct well but we are talking about huge potentials for small charges.

Shooting electrons into an existing material is easier by the way.

 

[marcusl]

Charges can be also injected by attaching metal contacts to opposing sides of a sample and applying a potential, as in a capacitor. The ability to inject charges into an insulator is severely limited by mutual Coulomb repulsion between them, however—the effect is called space-charge limiting.

 

[Henryk]

I don't think you could 'construct' a uniformly charge dielectric that way. There is no fundamental law that would prohibit that but it is rather unlikely process.
Still, there are devices that operate based on a trapped charge. These are the USB sticks, i.e. memories that can be programmed by injecting a charge into a structure made out of a conductor separated from the sensor by an insulating layer. These charges are trapped for a pretty good time.