We've frozen peppers for years, but I think you will find you get better (tastier) results by cooking them first and then freezing the cooked pepper. Ripe ones are better than green as the latter seem to acquire a more bitter taste.
If you have also got aubergines and tomatoes, why not make ratatouille which you can freeze in batches for use in the winter?
I'm going to try sun drying peppers this year by cutting them into strips and putting them in a south facing greenhouse for a few days. Never done this before so can't advise on whether it work equally well as freezing.

Many thanks Bertie