Structures including devices, such as transistors, integrated on a bulk semiconductor substrate and methods of forming a structure including devices, such as transistors, integrated on a bulk semiconductor substrate. The bulk semiconductor substrate contains a single-crystal semiconductor material having a diamond crystal lattice structure and a crystal orientation. A first transistor is formed in a first device region of the bulk semiconductor substrate, and a second transistor is formed in a second device region of the bulk semiconductor substrate. The second transistor includes a layer stack on the bulk semiconductor substrate, and the layer stack includes a layer comprised of a III-V compound semiconductor material.