Meyer-Neldel rule for Cu (I) diffusion in In2S3 layers

Abstract

The nature of barriers for atomic transport in In2S3 layers has been varied by addition of chlorine. Diffusion of Cu(I) from a removable CuSCN source was used to probe the variation of the barriers. The Meyer-Neldel (compensation) rule was observed with a Meyer-Neldel energy (EMN) and a proportionality prefactor (D00) amounting to 40 meV and 5 × 10−14 cm2/s, respectively. D00 shows that the elementary excitation step is independent of the specific mechanism and nature of the barrier including different densities of Cl in In2S3. The value of EMN implies that coupling of the diffusing species to an optical-phonon bath is the source of the multiple excitations supplying the energy to overcome the diffusion barriers.

Growth and thermal oxidation of Ru and ZrO2 thin films as oxidation protective layers

“…258 When applying this general explanation to solid state diffusion, which usually involves multiphonon processes, this rule can be interpreted as the increase of the number of paths to reach the activated state with increasing activation energy Ea. 259 This is due to the fact that ΔS is proportional to the logarithm of the number of paths of assembling the many excitations or the multiphonon processes. 260 Another explanation to this rule, is that multiple independent processes might contribute to the overall diffusion process (D), where an intrinsic transport process (for instance, by metal cations or oxygen anions) is the main contribution, and other mediated processes, such as amount of annealing or diffusion of impurities, are the minor contribution.…”