Over 1.5 million dissertations (mostly doctoral) from over 320 institutions, including UPEI, as of Oct 2023, in a free database from EBSCO. All of these should be free full text provided by a link to the institutional repository where that dissertation is stored.
This database is also included within the OneSearch discovery service.
Open Dissertations (public link for non-UPEI users)
For more information, see EBSCO's description.