Experimental study of negative differential conductivity in GaAs:Cr

作者：R. M. Rubinger, A. G. de Oliveira, J. C. Bezerra, G. M. Ribeiro, W. N. Rodrigues, M. V. B. Moreira · 发表于：Physical review. B, Condensed matter · 年份：2000 · DOI：10.1103/physrevb.62.1859 · 被引用次数：7 · 研究领域：Semiconductor materials and devices、Advancements in Semiconductor Devices and Circuit Design、Advanced Memory and Neural Computing

We have studied the temperature and illumination dependencies of the current versus voltage characteristics $I(V)$ of a Cr-doped GaAs sample. An S-shaped negative differential conductivity with a threshold at around 1 kV ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ was associated with a trap with activation energy of 90 meV. The low-conductivity state in $I(V)$ characteristics is strongly influenced by illumination and temperature. We also present evidence that the electrical conduction above the threshold electric field occurs by a mechanism that involves free electrons despite the fact that the low-conductivity state is p type. This supports the assumption that the 90 meV trap is a donor.