A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. [1] Its conductivity can be modified by adding impurities ("doping") to its crystal structure. When two regions with different doping levels are present in the same crystal, they form a semiconductor junction. However the term "semiconductors" is sometimes used to refer to semiconductor ...
A semi-detached house (often abbreviated to semi) is a single-family duplex dwelling that shares one common wall with its neighbour. The name distinguishes this style of construction from detached houses, with no shared walls, and terraced houses, with a shared wall on both sides.