Editing Electron hole (section)

== Role in semiconductor technology ==
[[File:Silicon doping - Type P.svg|thumb|An array of [[Silicon]] atoms [[Doping (semiconductor)|doped]] with [[Boron]] creates holes. This type of [[Extrinsic semiconductor|extrinsic semiconducting material]] is dubbed ''Type P''.]]
In some semiconductors, such as silicon, the hole's effective mass is dependent on a direction ([[Anisotropy|anisotropic]]), however a value averaged over all directions can be used for some macroscopic calculations.

In most semiconductors, the effective mass of a hole is much larger than that of an [[electron]]. This results in lower [[Electron mobility|mobility]] for holes under the influence of an [[electric field]] and this may slow down the speed of the electronic device made of that semiconductor. This is one major reason for adopting electrons as the primary charge carriers, whenever possible in semiconductor devices, rather than holes. This is also why [[NMOS logic]] is faster than [[PMOS logic]].
[[OLED]] screens have been modified to reduce imbalance resulting in non radiative recombination by adding extra layers and/or decreasing electron density on one plastic layer so electrons and holes precisely balance within the emission zone.  
However, in many semiconductor devices, both electrons ''and'' holes play an essential role. Examples include [[p–n diode]]s, [[Bipolar junction transistor|bipolar transistors]], and [[CMOS logic]].