| 摘要 |
<p>A semiconductor device characterised in that it comprises: (A) a layer of semiconductor material comprising an intermetallic semiconductor; and (B) a first barrier layer adjacent one side of the said semiconductor layer, which barrier layer comprises phosphorus is disclosed. Referring to the accompanying diagram, a semiconductor device 20 may comprise an intermetallic semiconductor layer 22 and barrier layers 23 and 24, the interface 26 causes a quantum well to develop. A method of making a quantum well device characterised in that it comprises depositing a barrier layer comprising phosphorus on an intermetallic semiconductor comprising a pnictide is also disclosed. Phosphorus and polyphosphides MPx, wherein M represents an alkali metal and x varies from 16 to infinity, have bandgaps larger than those of many of the currently used binary, ternary and quaternary semiconductors and have good interface properties therewith. Layers of phosphorus and such polyphosphides may be used as barriers in quantum well devices, particularly those using other semiconductor layers comprising a pnictide. The barrier layers may be, for example, MPx wherein x varies from 15 to infinity, M represents an alkali metal and P represents phosphorus. Phosphorus is the preferred barrier layer and may be monoclinic phosphorus, red phosphorus or amorphous phosphorus having a layer-like, puckered sheet-like local order. Quantum well and hetero-junction devices are further disclosed. These have applications in field effect devices,such as MESFETS, ring oscillators, two-dimension electron gas transistors, photodetectors and lasers. The present invention provides advantages over the prior art.</p> |
