one of the technique to make an object invisible..what do you think? will it work?

Not until you invent a darkon source, you won’t.

Does the “absence of light” work as “darkness,” in roughly the same way, in a semiconductor, an electron “hole” acts as a “positive charge?”

I’m thinking not, because darkness doesn’t have “sharp edges.” Any light nearby it kinda leaks into it and diminishes it.

(It’s like saying that “paint thinner” is a color… No, because any wet paint, nearby it, leaks into it, making it turn that color…)

But…I’m not sure… Close to right?