Tweet
A silicon light-emitting diode (LED) that can quickly switch between producing red and blue light could ultimately lead to smaller pixels for high-resolution displays.
LEDs can normally only emit light of one color. A new study shows that adding a certain rare earth metals can allow them to switch between two colors.
The new LED is made from a layer of semiconducting silicon and a layer of insulating silicon dioxide. This creates a 100-nanometre-thick barrier that obstructs the flow of electrons. Europium, a rare earth metal, is then implanted within the silicon dioxide.
Applying a voltage across the silicon dioxide barrier allows the electrons to cross the barrier - a quantum mechanical process known as "tunneling." While tunneling through the silicon, the electrons sometimes smack into the europium atoms, which sends them to a higher energy state. When these atoms fall back to their original state, they emit light.
LEDs can normally only emit light of one color. A new study shows that adding a certain rare earth metals can allow them to switch between two colors.
The new LED is made from a layer of semiconducting silicon and a layer of insulating silicon dioxide. This creates a 100-nanometre-thick barrier that obstructs the flow of electrons. Europium, a rare earth metal, is then implanted within the silicon dioxide.
Applying a voltage across the silicon dioxide barrier allows the electrons to cross the barrier - a quantum mechanical process known as "tunneling." While tunneling through the silicon, the electrons sometimes smack into the europium atoms, which sends them to a higher energy state. When these atoms fall back to their original state, they emit light.