There are various financial support options available. Please inform yourself on the corresponding pages:

The Potsdam Graduate School (PoGS) awards doctoral fellowships from funds of the graduate funding of the state of Brandenburg. More information and contact persons can be found on the website of the Postdam Graduate School. 

The Berlin School of Economics (BSE) awards scholarships within its structured PhD program. Please inform yourself on the pages of the BSE

You can also use the database of the Service Agency for ELectronic Research Funding Information System to search specifically for possible financial funding opportunities.