Answer
This is just an antialiasing issue, if you want perfectly sharp shapes that actually look smooth then please do what you need in illustrator, however, depending on the resolution, you will eventually end up with some grey areas, that is just the way our computer interprets smoothness.
If you still want to have only black spaces, you’ll end up with a pixelated look (Unless you work at a really really high resolution ), refer to this post for instructions on how to deactivate antialiasing
Attribution
Source : Link , Question Author : Aleppi , Answer Author : Community