Institute of High Pressure Physics

Refractive index engineering in GaN-based laser structures is quite a challenge because InN and AlN lattice constants significantly differ from GaN. This lattice mismatch is the reason why the chemical composition of epitaxial layers grown on GaN must be selected in such a way as not to generate mismatch defects.

InAlN with an indium composition of 17% is a good candidate for laser diode cladding layers, as it has a lower refractive index than GaN and is lattice-matched to the substrate. However, its fabrication is very difficult due to completely different optimal temperatures and pressures needed for the synthesis of its binary constituents InN and AlN.

In the publication “Science in times of transition” ("Nauka w czasach przemian”) prepared by the Foundation for Polish Science (FNP), dr inż. Marta Sawicka from our Institute tells about a project on improving the quality of InAlN grown by molecular beam epitaxy (MBE) supported by FNP. She also mentions a completely new idea - nanoporous GaN, which she and her research team implemented as a cladding layer in nitride lasers.

The publication is now available on the FNP website. It presents the achievements of more than 30 outstanding scientists whose research was supported by the FNP. Clicking the image below you will direclty open the publication. More about the project and the research team can be found on MBE Laboratory webpage.