Abstract

Tunable mid-infrared light is an efficient tool for probing molecular structures and medium energy bondings in various materials. Cr²⁺-dopped ZnSe is widely used for diode-pumped laser operation in the 2-3 μm wavelength range ^[1]. Due to its electrical properties, this material is also identified as a good candidate for electrically pumped emission. We report mid-infrared electroluminescence observed at room-temperature from a bulk ZnSe:Cr single crystal ^[2]. From a technological point of view, the ZnSe samples (typical dimensions 10 × 10 × 0.6 mm³) are Cr²⁺-doped up to concentrations of 10¹⁹cm⁻³, and gold electrodes are evaporated on both faces (Fig. 1). The light emission is obtained in an avalanche regime (corresponding to an impact ionization process), with a first-run electro-optical conversion efficiency of ~10⁻⁶ for an applied field of ~20kV.cm⁻¹ (Fig. 2a).

© 2007 IEEE