"things that team will do later" (TTWDL) ... bugs/ tasks from previous sprints. . . . open items from previous sprints.
I'm interested in what these items are.
If they're new work that you just didn't get to (eg, you descoped the sprint to finish within the timebox), then they definitely go back on the product backlog to be reprioritized later.
If they're items that were dinged against your acceptance criteria, I call those liens. I put them back in the product backlog, but tagged accordingly so that status is visible when we're prioritizing.
If they're cleanup tasks, to bring the code quality up to production standard now that you have an initial implementation, then the first thing I ask is, what's your Definition of Done? Does it include production quality elements (tests, documentation, responses to code review items, etc)? If not, then it should, and you need to include that when figuring how much scope you can get done in your timebox (or vice versa).
That aside, my team tends to put items like this in the technical debt pile, with the understanding that they'll be worked between sprints or as able, and the expectation that we may sometimes do a sprint whose goal is to reduce the technical debt.
If they're things that came up as additional good ideas during the sprint, definitely the product backlog.
If they're bugs that were discovered after the sprint was completed, then you might or might not have a separate process for handling bugs. If you don't, put 'em on the backlog, tagged as bugs and/or known issues so that is visible when prioritizing. You might sometime have a sprint whose goal is "squash bugs".