Andrew Klump is a fourth year Ph.D. student in the Materials Science & Engineering department working with Drs. Zlatko Sitar and Ramón Collazo. As a member of the Wide Bandgaps Laboratory, his research includes the MOCVD growth of III-nitrides with a particular focus on magnesium doping to achieve p-type conductivity. Prior to his time here at NC State University, he was a secondary ion mass spectrometry (SIMS) analyst working at EAG, where he first took an interest in the nitrides.
What primary instrument(s) are you using for your research and what do you like about it?
I work on the ION-TOF SIMS V instrument performing SIMS analysis of the nitrides grown in my lab group. There are three main ‘styles’ of SIMS – quadrupole, magnetic sector, and time-of-flight (TOF) – each has advantages and disadvantages for acquiring depth profiles for SIMS. At EAG I worked with a quadrupole system, so juxtaposing that with the TOF over the last four years has been a great experience. Definitely challenging/frustrating/rewarding all at the same time.
What have you been researching?
Typically, it is easy to dope a semiconductor either p- or n- type but not both. That holds true for the nitrides as well. I work on the problematic the p-type side trying to understand the compensation mechanisms at play. Most of my time has been spent growing Mg-doped GaN and characterizing the compensation levels as a function of growth conditions and doping.
How is your research impacting the community?
Mg-doping of GaN has had many published ‘observations’ but was lacking a good explanation that links all of that data. I believe my biggest impact has been to look at the entire body of literature on Mg-doping in the III-nitrides and provide that explanation. Beyond that I have begun studying p-type AlGaN, which has a lot of promise for UV-LEDs.
What have you learned from your experience at AIF?
The staff has an incredible amount of knowledge and experience! Ask any question and you are bound to learn something new.
Is there a staff member at AIF that has helped you?
Elaine Zhou and Fred Stevie. Similar to the previous point, they have been extremely helpful as both mentors and friends throughout my time at NC State.