| 摘要 |
PURPOSE:To assure good current-voltage-light emission characteristics by forming a hetero junction including a P type III-V compound semiconductor and an n type III-V compound semiconductor on a P type II-VI compound semiconductor crystal, and employing the P type II-VI compound semiconductor as a window for guiding light to the outside. CONSTITUTION:An InGaAsP four element mixed crystal double hetero junction is formed on a P type ZnSe crystal substrate 11 matching lattice constants for example. More specifically, a P type In1-x GaxAs1-yPy layer 12-In1-x Gax' As1-y'Py' layer 13-an N type In1-x''Gax''As1-y'' Py'' layer 14 are successively formed. The title element has a light emission wavelength of 610nm and is improved in external quantum efficiency 1.5%, three times larger compared with conventional cases. Further, the shape of the light emitting element is improved, i.e., the ZnSe crystal substrate 11 is formed into a semi-spherical shape from which light is taken out. Hereby, the external quantum efficiency is confirmed to be 17%. This is very luminous in this wavelength region and is improved in current-voltage-light emitting characteristics compared with a case where a light emitting diode is employed for deriving light. |
