search date when date is stored in the string format in db

I ma trying to filter data on date but I have stored the date in string format. I have coded it like this but it is not giving any result to me rather throws an error...

 // search attendance
    public function searchAttendance(Request $request)
    {
        $site_details = tbl_site::where("site_name", $request->site_name)->first();
        $query = tbl_master_attendance::query();
        $query->where("attendance_site_id", $site_details->site_id);
        $query->where(
            DB::Raw("STR_TO_DATE(attendance_date,'%d-%m-%Y')"),
            Carbon::parse($request->att_date)
        )->get();
        return $query;
        // return tbl_attendance::where("tbl_master_id", $attendance_master->master_attendances_id)->get();
    }