Order-disorder transition in epitaxial ZnSnP2

We report on the growth of ZnSnP2 on GaAs(100) substrates by gas source mol ecular beam epitaxy. Samples were grown in the temperature range of 300-360 degrees C. A small change in the Sn/Zn flux ratio at constant substrate te mperature was found to result in a transition from a lattice mismatched, De lta a/a similar to 0.4%-0.7%, disordered crystal structure to a lattice mat ched, ordered chalcopyrite structure. Infrared reflectance and Raman measur ements were used to monitor this phase transition. Formation of the two dif ferent crystal modifications is discussed in terms of vapor-solid and vapor -liquid-solid growth modes. (C) 1999 American Institute of Physics. [S0003- 6951(99)00515-X].