Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
HL: Fachverband Halbleiterphysik
HL 24: Nitrides: Preparation and characterization I
HL 24.1: Vortrag
Mittwoch, 3. April 2019, 09:30–09:45, H31
Band Offset at the Ga(N,As,P)/GaP Heterointerface — •Florian Dobener1,3, Sebastian Gies1, Jan O. Oelerich1, Peter Ludewig2, Kerstin Volz1, Stephan W. Koch1, Wolfgang Stolz1,2, Wolfram Heimbrodt1, and Sangam Chatterjee3 — 1Faculty of Physics and Material Sciences Center, Philipps-Universität Marburg, D-35032 Marburg — 2NAsP III/V GmbH, Am Knechtsacker 19, D-35041 Marburg — 3Institute of Experimental Physics I and Center for Materials Research, Justus-Liebig-University Giessen, D-35392 Gießen
We investigate a series of Ga(N,As,P) multiple quantum well samples grown by MOVPE. The well thickness is varied, while the composition is kept quasi-constant. The samples are examined by PL excitation spectroscopy to reveal the absorptive states in the sample, which contribute to the actual PL intensity. Besides higher states, we find two clear peaks slightly above the band-gap energy, which we attribute to the highest-energy heavy-hole valence band to lowest-energy conduction band energy and highest-energy light-hole valence band to lowest-energy conduction band energy transitions of the samples. Consequently, we are able to model the band offset between the Ga(N,As,P) quantum well and the GaP barrier with a band anti-crossing model and the model solid theory to attribute for strain in the sample. Additionally, depth-scan X-ray and UV photoelectron spectroscopy reveals the valence band-offset at the GaP/Si and Ga(N,As,P)/GaP interface, too. Overall, a rather shallow valence band offset is found by comparing the outcomes to the optical studies and to DFT calculations.