CHARACTERIZATION OF UNICOMPOSITIONAL GAINP2 ORDERING HETEROSTRUCTURESGROWN BY VARIATION OF V III RATIO/

Photoluminescence (PL) and photoluminescence excitation (PLE) spectros copies are employed to investigate single heterostructures based on tw o GaInP2 layers that have the same composition but different degrees o f order on the cation sublattice. Four sample configurations are studi ed: two complementary single heterostructures, a more ordered layer gr own on a less ordered layer and vice versa, and two single layers nomi nally equivalent co the constituent layers of the heterostructures. Th e degree of order of the two layers was controlled via the V/III ratio used during organometallic vapor phase epitaxial growth. From our mea surements, the difference between the band gaps of the two layers is 2 0-30 meV. The PLE spectra show clearly that the emission comes from bo th layers of the heterostructures and that the PL is excited by direct absorption of the exciting light into each layer as well as the injec tion of carriers from the less ordered (higher band gap) layer into th e more ordered (lower band gap) layer. The data clearly show that the heterostructures contain two layers, each very similar to the correspo nding single layer sample. (C) 1997 American Institute of Physics.