Revealing of InP multi-layer stacks from KPFM measurements in the dark and under illumination
Institut Photovoltaïque d'Ile de France, 30 Route Départementale 128, 91120 Palaiseau, France
2 Université Paris-Saclay, CentraleSupélec, CNRS, Laboratoire de Génie Electrique et Electronique de Paris, 91192 Gif-sur-Yvette, France
3 Sorbonne Université, CNRS, Laboratoire de Génie Electrique et Electronique de Paris, 75252 Paris, France
4 III-V Lab, 1 Avenue Augustin Fresnel, 97167 Palaiseau, France
* e-mail: firstname.lastname@example.org
Received in final form: 18 July 2022
Accepted: 28 July 2022
Published online: 23 August 2022
Solar cells are complex devices, being constituted of many layers and interfaces. The study and the comprehension of the mechanisms that take place at the interfaces is crucial for efficiency improvement. This paper applies Kelvin probe force microscopy (KPFM) to study materials and interfaces with nanometer scale imaging of the surface potential in the dark and under illumination. KPFM measurements are highly sensitive to surface states and to the experimental measurement environment influencing the atomic probe operating conditions. Therefore, in order to develop a quantitative understanding of KPFM measurements, we have prepared a dedicated structured sample with alternating layers of InP:S and InP:Fe whose doping densities were determined by secondary-ion mass spectroscopy. We have performed KPFM measurements and shown that we can spatially resolve 20 nm thick InP layers, notably when performed under illumination which is well-known to reduce the surface band-bending.
Key words: Kelvin probe force microscopy / III-V multilayer stack / surface photovoltage
© M. da Lisca et al., Published by EDP Sciences, 2022
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