In this work we look into how the contact material influences the local charge properties of a p-type CdTe-based quantum well. We study five metals deposited as 10 nm layers on the sample surface: Au, Ag, Cr, Ni and Ti. We use magneto-spectroscopy to discriminate their charge states through monitoring the Zeeman shifts at singlet-triplet transitions. Most tested metals retain the original p-type of the QW, while gold and nickel coverage flips the local doping to n-type. This is attributed to a robust bonding of these two metals to the semiconductor, efficiently passivating its surface and thus improving electron diffusion from the metal to the quantum well.
@article{arxiv.2512.04631,
title = {Hole to Electron Crossover in a (Cd,Mn)Te Quantum Well through Surface Metallization},
author = {Amadeusz Dydniański and Mateusz Raczyński and Aleksandra Łopion and Tomasz Kazimierczuk and Jacek Kasprzak and Karolina Ewa Połczyńska and Wojciech Pacuski and Piotr Kossacki},
journal= {arXiv preprint arXiv:2512.04631},
year = {2025}
}