How to do a Linq left outer join

I have the following ling join, where I tired to do a left join

    var result = (from dataRows1 in listP
                                  join dataRows2 in listV.Where(d => d.BusinessDate != null)
                                  on new { ID = dataRows1.ID, BusDate = dataRows1.BusinessDate } equals
                                     new { ID = dataRows2.ID, BusDate = dataRows2.BusinessDate }

                                  select new T
                                                  {
                                                    BookPrice =  dataRows1.BookPrice,,
                                                      RateApplied = dateRows2.Rate
                                                  }.DefaultIfEmpty().ToList();

But it stilldoes a join.

I have 8000 rows in LisP, and 7000 rows in ListV, I would expect that I get back 8000 rows in my result