Optical properties of AgxCu1–xI alloy thin films

Abstract

We report on the excitonic transition energy E0 and spin–orbit split-off energy Δ0 of γ-Ag xCu1– xI alloy thin films studied by using reflectivity measurements at temperatures between 20 K and 290 K. The observed bowing behavior of the E0 transition as a function of the alloy composition is explained based on first-principles band structure calculations in terms of different physical and chemical contributions within the description of ordered alloys. The spin–orbit coupling is found to increase from a value of 640 meV for CuI to approximately 790 meV for AgI. Furthermore, we show that the temperature-dependent bandgap shift between 20 K and 290 K decreases with increasing Ag-content from 25 meV for CuI to 6 meV for AgI. We attribute this behavior mostly to changes in the contribution of thermal lattice expansion to the bandgap shift.

Ni‐Alloyed Copper Iodide Thin Films: Microstructural Features and Functional Performance

“…We focused on describing ordered alloys, using 2Â2Â2 primitive supercells (comprising 8 atoms of Ni and Cu each, along with 8 I atoms).With this computationally efficient approach, results in excellent agreement with experiments have already been obtained in the case of Ag x Cu 1Àx I alloys. [31] A planewave basis set with a cutoff energy of 700 eV and a k-point grid of 4Â4Â4 were used, satisfying a convergence criterion of 1 meV atom À1 for the total energy. Both, the crystal structure and the magnetic moments, were relaxed using the PBEsol functional [32] until all forces were less than 1 meV Å À1 .…”

“…We focused on describing ordered alloys, using 222 primitive supercells (comprising 8 atoms of Ni and Cu each, along with 8 I atoms).With this computationally efficient approach, results in excellent agreement with experiments have already been obtained in the case of alloys. [ 31 ]…”

Computational prediction and characterization of CuI-based ternary p-type transparent conductors

“…The MHM allows us to search in an unbiased way for new crystal structures, expanding significantly the search space in comparison to previous works on CuI alloys focused on zinc blende phases. 45–47 Following this path, we expect to find new compounds with promising properties and unveil alternative ways to control the electronic properties of CuI-based TCM.…”