Photoemission Spectroscopy for Halide Perovskites Semiconductors
Philip Schuz a
a CNRS, École Polytechnique, IPVF, UMR 9006, FR, 30 RD 128, 91120 PALAISEAU,, France
Proceedings of Interfaces in Organic and Hybrid Thin-Film Optoelectronics (INFORM)
València, Spain, 2019 March 5th - 7th
Organizers: Natalie Stingelin, Henk Bolink and Michele Sessolo
Invited Speaker, Philip Schuz, presentation 043
DOI: https://doi.org/10.29363/nanoge.inform.2019.043
Publication date: 8th January 2019

For many semiconductor applications photoemission spectroscopy (PES) play the role of an invaluable tool to determine key electronic parameters for the description of the device functionality, such as band offsets and interface dipoles. With the rise of photovoltaic technologies based on halide perovskite (HaP) absorber layers, the use of direct and inverse PES methods has been pursued to monitor the formation of interfaces between halide perovskite films and adjacent functional layers, that are employed for charge transfer in perovskite-based optoelectronic devices.

We reported on the energy level alignment between HaP films and organic charge transport layers [1], oxide substrates [2], carbon nanotube thin-films [3] and high-work function MoO3 overlayers [4]. In this talk I will summarize these findings and describe the challenges to generalize these trends as the complex chemistry between HaP layer and adjacent semiconductor often lies at the root of the observed interfacial alignment processes and band bending.

Furthermore, I will give examples for typical pitfalls that occur, when characterizing HaP surfaces and interfaces with PES methods. Most importantly, beam damages effects have been identified as the perovskite layers can exhibit distinct signs of degradation under vacuum conditions and concomitant irradiation with high-energy photons [5]. While we generally intend to avoid these transient effects in our measurements, we can extract additional physical and chemical parameters from the evolution of energy level positions and stoichiometry during the PES measurements [6-8], with direct implications on the material stability. Finally, I will conclude my talk with a view on the perspectives of interfacial analysis for halide perovskites by PES techniques and an outlook on future experiments [9].

P.S. thanks the French Agence Nationale de la Recherche for funding under the contract number ANR-17-MPGA-0012

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info