| 摘要 |
1,214,655. Electroluminescence. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 19 Dec., 1967 [21 Dec., 1966 (2)], No. 57575/67. HeadingC4S. An e.1. diode comprises an e.c. crystal having a flat junction 3 intersecting side faces 4 arranged at angles to the crystal axis such that all normals to the faces in the immediate vicinity of the junction extend from the surface on one side of the junction, the crystal having a strong refractive index gradient normal to the juncjunction such that radiation is guided along the plane of the junction and emanates mostly through surfaces adjacent the intersection of the junction and faces 4. A frusto-conical Zn diffusion doped GaAs crystal has Cu contacts 5, 6 soldered to its flat surfaces, contact 6 acting as a heat sink. The crystal has its apex angle A greater than the critical angle so that radiation from the junction emerges only from the region 1 which has n-type conductivity with a low free charge. This passes only a narrow spectrum of radiation but has a high tranmission. If a wide spectrum is required the apex angle is reduced allowing light from both sides of the junction to emerge and electrode 5 is replaced by a metal ring around the conical face which permits radiation to emerge from the end face 7. Projectors may comprise a frusto-conical crystal in the focal plane of a paraboloidal mirror or a pyramidal diode and a parabolic mirror, an ellipsoid mirror is referred to. The crystal may be surrounded by air liquid or solid. The crystal need not be a body of revolution or symmetrical and the section shown of the diode may be curved except near the junction. |
