Tables having one to many relationship generates outer join

I have 2 tables

public class Department : DbContext
{
   public int DeptId {get; set;}
   public string DeptName {get; set;}
   public virtual List<Student> Students {get; set;}
}

public class Student: DbContext
{
   public int StudentId {get; set;}
   public string StudentName {get; set;}
   public int DeptId {get; set;}
   public virtual Department Department {get; set;}
}

So a department can have multiple students But I want to join and convert all the data into below structure

public class CollegeData
{
   public int DeptId {get; set;}
   public string DeptName {get; set;}
   public List<StudentData> Students {get; set;}
}

public class StudentData
{
   public int StudentId {get; set;}
   public string StudentName {get; set;}
}

I wrote the below query to get the joined data

var data = (from dept in _dbContext.Department 
            select new CollegeData
            {
              DeptId = dept.DeptId,
              DeptName = dept.DeptName,
              Students = (from student in _dbContext.Student
                          where student.DeptId == dept.DeptId
                          select new StudentData
                          {
                             StudentId = student.StudentId,
                             StudentName = student.StudentName
                          }).ToList()
            }).ToList();

But when I am profiling this, it is creating left join query. I will need inner join query in this use case

Can somebody give me a direction for this?