What is the white powder on the glass inside a television?

We just broke a television open and there is white powdery stuff on the inside of some of the screen.

Not really sure but I think it is what reacts with the electrons fired at it and lights up making the picture on the other side. I also believe its toxic.

I believe it may be dust or phosphorous.

dont snort it, its not cocaine and stop fighting in the house, take it outside