Meeting the People: Zhenyu Wang

Zhenyu Wang gave insights to the Understanding cation distribution in Zn1+xGeN2Ox        (x < 0.1) at the 1st Joint Polish-German Crystallographic Meeting 2020 in Wrocław/Poland. His lightning talk and poster presentation was awarded with a Presentation Award. Here, he will tell us about his work.

Poster from Zhenyu Wang in the Corporate Deisgn of Helmholtz-Zentrum Berlin. Co-authors are Joachim Breternitz, Alexandra Franz and Susan Schorr. Introduction: Zn-IV-N2(IV: Si, Ge, Sn) materials are being considered as potential candidates for photovoltaic absorber materials, since they are earth-abundant and non-toxic alternatives to commercially important (Ga,In)N semiconductors.[1]They show a distinct bandgap tuning mechanism through cation disorder in addition to the possibility of cation alloying.[2] A similar effect is achieved through oxygen incorporation.[3]We use the oxygen incorporation into ZnGeN2to engineer cation disorder in a bulk material system to adapt the investigation of cation disorder in order to gain a comprehensive insight into cation order/disorder effects. Zn1+xGe1-x(N1-xOx)2powder samples were prepared by ammonolysis reaction of Zn2GeO4precursors under NH3flow at a temperature range from 835 °C to 910 °C.[3]

What fascinates you about cation distribution?

Regarding the disorder research in these ternary nitrides, the cation disorder is very interesting since it triggers a unique bandgap tunning mechanism in addition to alloying with other elements. It could allow a fascinating insight into this kind of structure-property relation.

How did you end up in semiconductor research?

During my master study, I interned in a project on a thermoelectric semiconductor as an internship student in IFAM Dresden. I met respectable supervisors and colleagues there. Since then, I have become interested in semiconductors. After that, my experience so far half comes from choices based on interests and half comes from luck.

Does the poster represent the full extent of your work or is there even more about it – for example a greater context inside the team?

The poster shows part of my work. We have also done some other works, including the study of the reaction mechanism of the synthesis process, DFT analysis on disorders and more. Recently we have made some progress in the optimization of synthetic methods on the ternary nitrides. Maybe next time I will be able to share something new with you if I have the opportunity. Some colleagues in our group have also done some interesting study of disorders in crystal structures. For example, we have Galina who is an expert on kesterite and chalcopyrite, Danial working on DFT calculation including disorder materials, and Joachim who finds some interesting explanations of piezoelectric performance in perovskite in crystallographic aspect etc.