Dear @Masiraha,
thank you for sharing your question with the Wefugees Community.
While your asylum case is pending in Germany, you are unfortunately not allowed to move to another country, including to the Schengen member countries, to do your PhD or to work there.
I hope, you have got your answer. I am a MBEON consultant. If you wish to contact me directly, you can see my profile and follow the instructions there.
Best wishes
Fardeen Noori