Resistivity of semiconductors [1] is between that of conductors [2] and insulating materials [3], being a value between ρ = 10-2…10+9 Ωcm in standard state, in other words these materials are poor insulators and weak conductors of  electricity. Semiconductors behave like insulating materials at low temperature.
Another typical property of semiconductors is that their resistance is dependent on temperature. Their resistance declines exponentially with rising temperature.
The higher their temperature, the better they conduct electricity. (It is the other way round with metals.)
Silicon is the most frequently used semiconductor. Semiconductors used in a broad range of applications beside silicon are compound type materials from the elements of the Group 3 to 5 of the periodic table. Conductance and optical properties of compound type semiconductors may differ from those of pure (intrinsic) semiconductors substantially.
Traits characteristic for semiconductors are shown by Al (aluminium), Ga (gallium), In (indium) in Group 3a; C (carbon), Si (silicon), Ge (germanium), Sn (tin) from Group 4a; and N (nitrogen), P (phosphorus), As (arsenic), Sb (antimony) from 5a, respectively.
The material in LEDs for instance will be typically a binary compound. In the order of shortening wave length of the light emitted: GaAs, AlGaAs, GaAsP, GaP, GaN, ZnSe, InGaN, SiC, C (diamond). Ternary and quaternary semiconductors also have important practical applications: (AlxGa1−x)As, (InxGa1−x)As, (AlxGa1−x)N, (InxGa1−x)N or In1−xGaxAs1−yPy, (AlxInyGa1−x−y)P, (AlxInyGa1−x−y)N, Si1−x−yGexCy , as well as Si1−x−y−zGexCySnz.

You also have to mention the organic semiconductors, which are gaining ground in electronics more and more.
Organic semiconductors are used on a larger scale in photonics to manufacture for instance LEDs and LED based displays. Even though inorganic semiconductors are smaller and more sensitive than their counterparts derived from organic compounds, organic semiconductor devices can be produced more cost effectively in the form of n-type layers, and mechanically flexible opto-electronic parts of reasonable quality can be made from them.
Organic semiconductors have two main varieties. One consists of small organic molecules such as pentacene, containing five linearly connected benzene rings, the other of connecting conjugated polymer chains, such as polyacethylene, which has a hundred or a thousand carbon atoms.
Organic semiconductors must also be doped. Frequently used impurities include sodium and iodine.

[1] University of Cambridge: Introduction to Semiconductors
[2] conductors: ρ = 10-9…10-2 Ωcm 
[3] insulators: ρ = 10+9…10+18 Ωcm