I have a temporary residence permit (fiktionsbescheinigung), valid for the next six months, which I got in Germany under § 81 Section 4 of the Residence Act. Can I travel to Switzerland with this certificate (bescheinigung)?
This depends on your Fiktionsbescheinigung as described in german on this official document
You have three boxes, which can be ticked on page three.
If the first or second are ticked you are not allowed to enter Switzerland without a visa
If the third one is ticked, you may enter switzerland with an official expired "Aufenthaltsbewilligung" or a Visa.
So long story short: You probably need a Passport with a valid visa inside.