Blue Electroluminescenee from a ZnSe MIS Structure

Photoluminescence properties of ZnSe single crystals grown by the high pressure Bridgman method and injection electroluminescence in a ZnSe MIS structure have been studied. A ZnSe crystal heat-treated in molten Zn shows an exciton (2.786 eV), free-to-bound (2.705 eV) and self-activated (2.066 eV) emission at 90 K, and the EX(2.666 eV) anti the SA(2.123 eV) emission at 300 K. An insulator layer has been fabricated by rf-sputtering of a SiO 2 . film on ZnSe, and a Au–SiO 2 –ZnSe diode has been constructed. The diode shows only blue emission peaking at 2.666 eV at room temperature. The best value for the external quantum efficiency is about 10 -5 for a SiO 2 . film about 0.1 µm thick at room temperature. At 90 K, the diode has three emission bands at 2.76, 2.705 and 2.066 eV. The higher intensity of excitation makes the higher energy emission more intensive.