A virtual substrate structure includes a crystalline silicon substrate with a first layer of III-N grown on the silicon substrate. Ge clusters or quantum dots are grown on the first layer of III-N and a second layer of III-N is grown on the Ge clusters or quantum dots and any portions of the first layer of III-N exposed between the Ge clusters or quantum dots. Additional alternating Ge clusters or quantum dots and layers of III-N are grown on the second layer of III-N forming an upper surface of III-N. Generally, the additional alternating layers of Ge clusters or quantum dots and layers of III-N are continued until dislocations in the III-N adjacent the upper surface are substantially eliminated.