+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
 
News Article

US team delivers evidence for p-doped InN

The development of AlInN-based solar cells, lasers and LEDs has received a boost from scientists in the US who have obtained the first evidence for p-type InN.

A partnership between Lawrence Berkeley National Laboratory, Cornell University and the University of California, Berkeley, claims that it has produced the first evidence for p-doping in InN films ( Phys. Rev. Lett. 96 125505).

The work could aid the development of solar cells, LEDs, and laser diodes based on the AlInN material system that has an exceptionally wide direct band gap range (0.7-6.2 eV). n-type InN growth is already established, but p-type material is also needed for device fabrication.

The team grew the 500 nm-thick InN films on sapphire substrates and a 200 nm-thick GaN buffer layer using MBE and a magnesium dopant.

Various techniques were used to establish the film's p-type doping, but in each case the measurements were hampered by n-type conductivity of the surface accumulation layer.

According to the team their experiments showed that their InN films had a net concentration of acceptors in the bulk material below the surface, but the measurements could not verify the presence of free holes.

Capacitance-voltage measurements were used to infer that the film's magnesium-doping level was "in the low 1019 cm-3 range", which suggests that 1-10% of the magnesium dopant atoms act as acceptors.

Transport and photoluminescence measurements provided additional evidence for p-type doping in InN. For example, photoluminescence intensity measurements showed that a dose of helium ions could offset the affect of p-type acceptors introduced by magnesium-doping.

Cornell University's William Schaff said that the team has recently developed techniques that reduce the affect of the n-type surface accumulation layer, which will aid the researchers development of AlInN-based solar cells.

×
Search the news archive

To close this popup you can press escape or click the close icon.
×
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: