Dr Markus Pristovsek

Markus left the group at the very beginning of 2017 to take up a designated professorship at Nagoya university in Japan. His ResearchGate profile is here for more up to date information on his work.

Light onto the black art of semiconductor nanostructure formation

From 1989 I studied basic physics at the technical university of berlin. In 1995 I obtained my Diploma at Prof. Richter’s Group about Growth and Passivation of III-V-Semiconductors. The group was the leading group to built and use Reflectance Anisotroy Spectroscopy (RAS) to study classical III-V semiconductor growth in metal-organic vapor phase epitaxy, the workhorse of III-V semiconductor nanostructure growth. I did my PhD also in the same group in 2000.

The in-situ monitoring was quite successful and led to the foundation of the company LayTec which is thriving today. Not least because nitride semiconductor growth requires good in-situ monitoring for success.

In 2000 just after I got my PhD, I did not join LayTec but I went to Tsukuba, Japan. There I worked as a Postdoc at the National Institute for Materials Science on in-situ characterisation with RAS but also with in-situ Scanning Tunneling Microscopy (STM). The latter allows in principle to follow single atoms on the surface. Back in Berlin, after a short stay at the Ferdinand-Braun-Institut für Höchstfrequenztechnik I joined again the TU Berlin where I led the MOVPE activities.

New materials such as InN and novel ferromagnetic semiconductors like InAsP:Mn with a tailorable Mn acceptor depth were investigated, with the main focus on the growth process. A very special result was the first and only in-situ STM for MOVPE. This is up to date the only STM worldwide that can operate at 700°C near atmospheric pressure. Other innovative tools were the only multi-channel RAS setup for semiconductor epitaxy, and three spectroscopic ellipsometers for during growth studies.

In recent years the growth of nitrides for solid state lightning, laser diodes, and ultra-violett diodes for water purification became challenging not only from an academic point of view but with a several billion heavy industrial perspective. Thus now even politicians come to start up a new MOVPE lab: The photo on top shows me with the Science Minister David Willets at the opening of the new 6×2 reactor, which we hosted at the Cavendish laboratory and has been recently moved to Materials Science.

Consequently large efforts are devoted worldwide into research of nitride semiconductor growth and device development. All this relies on nanostructures inside the current devices which are typically less than 10 atoms in height. Therefore understanding and ultimatively controlling of surfaces and interfaces is needed now more than ever.