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HL: Fachverband Halbleiterphysik
HL 7: Poster I
HL 7.10: Poster
Monday, March 27, 2023, 13:00–15:00, P2/EG
Band energy diagrams of n-GaInP/n-AlInP(100) surfaces and heterointerfaces — •Mohammad Amin Zare Pour1, Oleksandr Romanyuk2, Dominik C. Moritz3, Agnieszka Paszuk1, Clément Maheu3, Sahar Shekarabi1, Kai Daniel Hanke1, David Ostheimer1, Thomas Mayer3, Jan P. Hofmann3, Wolfram Jaegermann3, and Thomas Hannappel1 — 1Technische Universität Ilmenau, Ilmenau, Germany — 2Institute of Physics of the Czech Academy of Sciences, Prague, Czech Republic — 3Technical University of Darmstadt, Darmstadt, Germany
n-AlInP(100) charge selective contacts are commonly grown on n-p GaInP(100) top absorbers in high-efficiency III-V multijunction solar or photoelectrochemical cells. Understanding the atomic and electronic properties of the GaInP/AlInP heterointerface is crucial for the reduction of photocurrent losses in multijunction devices. We investigated chemical composition and electronic properties of n-GaInP/n-AlInP heterostructures by X-ray photoelectron spectroscopy (XPS). 1-50 nm thick n-AlInP(100) epitaxial layers were grown on n-GaInP(100) buffer layer on n-GaAs(100) substrates by metal organic vapor phase epitaxy. We observed (2x2)/c(4x2) low-energy electron diffraction patterns on both AlInP(100) and GaInP(100) as-prepared surfaces. An upward surface band bending probably caused by localized mid-gap electronic states was observed. Pinning of the Fermi level by localized electronic states remained in n-GaInP/n-AlInP heterostructures. A valence band offset of +0.2 eV was derived by XPS and band diagram models for the n-n junctions were suggested.