Epitaxial Growth of AgxCu1-xI on Al2O3(0001)

Herein, the epitaxial growth of Ag x Cu 1-x I alloy layers and isolated small crystals on Al 2 O3 (0001) using close distance sublimation (CDS) technique is presented. Single-phase gamma- Ag x Cu 1-x I thin films are fabricated up to an Ag content of x approximate to 0.5 , while at higher Ag contents the beta-phase is also observed. The epitaxial relationships between the deposited Ag x Cu 1-x I layers and the Al 2 O3 substrate as well as the structure type are discussed for different alloy compositions. In addition, a further approach is presented for deposition of polycrystalline single-phase gamma- Ag x Cu 1-x I thin films for Ag contents up to x approximate to 0.7 based on the solid-state reaction of AgI layers on Al 2 O3 (0001) substrate with CuI. Furthermore, for differently prepared samples it is shown that the near-band-edge emission at 2 K is dominated by excitonic recombination, whereas the spectral position of the emission profile can be tuned by the alloy composition.