| 摘要 |
<p>PURPOSE:To achieve low-voltage photoswitching operation of a phototransistor by a method wherein the mean refractive index of a quantum well structure is set up to exceed those of an emitter layer, base layer and collector layer. CONSTITUTION:A collector layer 2, multiple quantum well layers 3, a base layer 4, an emitter layer 5, and a cap layer 6 are successively crystal-grown on an n-GaAs substrate 1. Next, partial photoetching is done to expose the base layer 4. The layer 3 is shaped into stripes to form a collector layer 7, a base electrode 8 and an emitter electrode 9. At this time, if the film thickness and composition of quantum well and barrier of the multiple quantum well structure 3 are set up so that the mean refractive index of multiple the quantum well structure 3 may exceed those of the collector layer 2, base layer 4 and emitter layer 5, then incident light 10 is led to the multiple quantum structure 3 and output light 11 is obtained. Through these procedures, photoswitching operation is enabled to be performed at low signal voltage making use of the amplification of a transistor.</p> |
