welcome to the Wefugees community and thank you for sharing your question with us.
At first, congratulations on your PhD.
Generally spoken, you can obtain the German citizenship after 6-8 years. If you opt for the earliest possible naturalization, just check if you meet the following conditions:
- 60 months of regular work that was subject to social contributions (you can check this easily in the pension information you are sent once a year)
- at least a B1-certificate
- a certificate of the naturalization test (you can find the questions here: http://oet.bamf.de/pls/oetut/f?p=514:1:7564603398133:::::)
- secure livelihood
- sufficient living space
A B2- or C1-certificate or other proofs (like voluntary work) of excellent integration will help you to reduce the period. The PhD itself is a sign of a considerable integration effort, but it won't exempt you from the naturalization test.
As you've been living here for five years now and apparently comply with the first prerequisite, you should contact your immigration authority. They will give you a checklist will all the documents needed.
I hope my answers were useful for you and I'll be very pleased if you contact me again with further questions. I'm a member of the mbeon-staff and I‘ll be glad to guide over a longer period of time. mbeon is an online advisory service for migrants via the mbeon-app, which you can install on your smartphone for free. Download it via Google Play Store (https://play.google.com/store/apps/details?id=de.zone35.mbeon) or the App Store
You'll find me in the mbeon-app under my name „München, Frau Müller“ and get confidential one-to-one advice in a safe virtual room where nobody can read messages. For more information please visit www.mbeon.de.