Laser screens of ZnSe produced by bridgeman method

Zinc selenide, a rectizonal semiconductor of the AIIBVI group with a 2.7 electron volt forbidden zone width at 300 K, is studied as a material for laser screens. Cathode luminescene of the initial samples was studied to establish the connection between the resulting spectra and laser screen generation parameters. Results indicated that impurities were eliminated by the crystallization process, which yielded a crystal that diverged from stoichiometry in the direction of excess selenium. Spectral data gathered during production and during laser generation confirm that ZnSe produced by this method can be used to make laser screens with threshold current density of up to 40 A/square centimeters and efficiency of up to 3% at ca. 100 A/square centimeters. Cathode luminescence was an effective criterion for material quality control. Reduced threshold current could be obtained by reducing the concentration of zinc vacancies in the compound's stoichiometry.