Dresden 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HL: Fachverband Halbleiterphysik

HL 12: Heterostructures, Interfaces and Surfaces: Photonics

HL 12.4: Talk

Monday, March 9, 2026, 17:30–17:45, POT/0051

Metal-oxide passivation for high-efficiency photoelectrochemical devices — •Negin Mogharehabed¹, Mohammad Amin Zare Pour^1,2, Christian Höhn³, Roel van de Krol³, Thomas Hannappel², and Agnieszka Paszuk¹ — ¹BMFTR Junior Research Group PARASOL, Technische Universität Ilmenau, Germany — ²Fundamentals of Energy Materials, Technische Universität Ilmenau, Germany — ³Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Germany

Thin metal-oxide protection layers are crucial in highly efficient III-V photoelectrochemical (PEC) devices to suppress interfacial recombination and ensure long-term stability. Here, we study TiO₂ layers deposited on AlInP/GaInP(100) photoabsorbers, examining how surface preparation prior to atomic layer deposition and the Ti-precursor chemistry affect the chemical composition and band alignment at the TiO₂/III-V heterointerface, as well as the TiO₂ bulk and surface properties. Before TiO₂ deposition, the native oxide on AlInP(100) was removed by wet-chemical etching. TiO₂ films were grown using either TTIP or TiCl₄ with H₂O at various substrate temperatures. X-ray photoelectron spectroscopy was used to characterize the interface and TiO₂ bulk composition. We observe precursor-dependent differences in contaminant species in the TiO₂ bulk, at the surface, and at the TiO₂/III-V heterointerface, while their concentration is strongly influenced by deposition temperature and post-growth annealing. Finally, we correlate precursor choice and initial surface condition with TiO₂ layer stability in aqueous electrolytes under PEC-relevant conditions.

Keywords: metal oxide passivation layer; titanium dioxide; III-V semiconductors; photoelectrochemistry; X-ray photoelectron spectroscopy