Regensburg 2016 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 35: Poster I

HL 35.32: Poster

Tuesday, March 8, 2016, 15:00–19:00, Poster A

Optical Characterization of GaN:Fe — •Sebastian Bauer¹, Matthias Hocker¹, Benjamin Neuschl¹, Maria L. Gödecke¹, Martin Klein², Frank Lipski², Eberhard Richter³, Ferdinand Scholz², and Klaus Thonke¹ — ¹Institute of Quantum Matter, Semiconductor Physics Group, University Ulm — ²Institute of Optoelectronics, University Ulm — ³Ferdinand-Braun Institute, Berlin

Nominally undoped GaN is typically n-type in the range of some [n]=10¹⁶-10¹⁹ cm⁻³ carriers introduced by uncontrolled silicon and oxygen impurities. To remove this background conductivity, incorporation of iron on Ga sites acting as deep acceptors is a viable way to create so-called semi-insulating material, similar to semi-insulating GaAs:Fe. The electrical Fe²⁺/Fe³⁺ level associated with Fe in GaN is located some 0.6 eV below the conduction band.

In the present study we present electrical and mainly optical data of thick GaN:Fe layers grown by hydride vapour phase epitaxy, using a ferrocen source for Fe. The samples show different concentrations of iron and background donors incorporated, and thus different degrees of compensation. In optical absorption measurements, we established – based on secondary ion mass spectrometry and electrical data – a correlation between the absorption signal and the actually present compensation status of iron.