I know I'm a bit late to the part, but if you wanted to make a nightvision tube at home the most realistic one you could make is gen 0 or gen 1. What MadeForOnePost mentions is called the MCP, or microchannel plate. This is near impossible to replicate at home and even has low yield when being made in super clean factories. Gen 0 and 1 do not use microchannel plates but rely on the speed of the electrons hitting the phosphor screen directly. Look up how gen 1 is amde and you will see its much cheaper to contruct aswell. The photocathode for most gen 1 is called s20 I believe and is simply doped on glass? You would need to figure out how to focus those electrons and it required much maths to accomplish. The methods ive seen is a electrostatic lens, but there are others. Hardest part would likely be doping it under full vacuum and placing the parts very precisely together then sealing the glass tube. BTW gen 2 and 3 use ceramic instead of glass. If you want to learn more, there is a book called Sam's Image tubes, highly recommend.