Semiconductors can be conductors or insulators.
This depends on the internal structure of a semiconductor,
but also on the external influences.
This results in interesting physical properties and applications.
The electroluminescence is the basis of all LEDs.
On applying a voltage to a semiconductor, you observe light.
Here you find out the most important
characteristics of electroluminescence
and where it is employed.
The photovoltaic effect is the basis of all solar cells.
With a solar cell you are able to convert sunlight into electrical energy.
Here you discover some properties of the photovoltaic effect.