Ionic-to-Electronic Conductivity Crossover in CdTe-AgI-As2Te3 Glasses An 110mAg Tracer Diffusion Study

M. Kassem (1) , I. Alekseev , M. Bokova (1) , David Le Coq (2) , E. Bychkov (1)

1 LPCA - Laboratoire de Physico-Chimie de l'Atmosphère
2 ISCR - Institut des Sciences Chimiques de Rennes

Conductivity isotherms of (CdTe) (AgI)(AsTe) glasses (0.0 ≤ x ≤ 0.15) reveal a nonmonotonic behavior with increasing CdTe content reminiscent of mixed cation effect in oxide and chalcogenide glasses. Nevertheless, the apparent similarity appears to be partly incorrect. Using Ag tracer diffusion measurements, we show that semiconducting CdTe additions produce a dual effect: (i) decreasing the Ag ion transport by a factor of ≈200 with a simultaneous increase of the diffusion activation energy and (ii) increasing the electronic conductivity by 1.5 orders of magnitude. Consequently, the conductivity minimum at x = 0.05 reflects an ionic-to-electronic transport crossover; the silver-ion transport number decreases by 3 orders of magnitude with increasing x.

Keywords: Chalcogenide glass; Diffusion; Semiconducting cadmium telluride; Semiconducting silver compounds; II-VI semiconductors; Glass; Electric conductivity; Metal ions; Silver halides; Orders of magnitude; Tracer diffusion; Electronic transport; Electronic conductivity; Diffusion activation energy; Semiconducting tellurium compounds; Activation energy; Cadmium telluride; Ion transports; Nonmonotonic behaviors

Domains: Chemical Sciences; Material chemistry

M. Kassem, I. Alekseev, M. Bokova, David Le Coq, E. Bychkov. Ionic-to-Electronic Conductivity Crossover in CdTe-AgI-As2Te3 Glasses An 110mAg Tracer Diffusion Study. Journal of Physical Chemistry B, 2018, 122 (14), pp.4179-4186. ⟨10.1021/acs.jpcb.8b00739⟩. ⟨hal-01809150⟩