Interface Formation between Metal Halide Perovskites and Oxide Films from Atomic Layer Deposition
We will use hard X-ray photoelectron spectroscopy (HAXPES) measurements to investigate the chemistry and defect formation at the interface between metal halide perovskite thin films and oxide layers grown by atomic layer deposition. We will track reactions at the buried interface and introduce interlayers that protect against the impact of the deposition process.
Status: Ongoing
Date of proposal: 28/02/2023
Start date: 07/03/2023
End Date: 12/03/2023
Used Instruments: LabXPS. Synchrotron-based HAXPES (High-Energy X-ray Photoelectron Spectroscopy).
Experimental Technique: Atomic Layer Deposition (ALD) for NiOx. X-ray Photoelectron Spectroscopy (LabXPS and HAXPES).
Experiment Description: Investigation of the interface formation between metal halide perovskites and oxide films from ALD. Analysis of the chemical composition, energy level alignment, and band bending at the buried interface between the oxide layer and metal halide perovskite film. Study of the interaction between perovskite surface and ALD NiOx precursors.
Type Samples: Thin NiO layers deposited on metal halide perovskite thin-films. Samples with and without a polymeric film of PTAA as an interlayer.
Sample Description: N-i-p configuration perovskite solar cells with ALD-NiOx hole-transport interlayer. Samples with varying configurations and interlayers for detailed interface analysis.
Experiment Data Type: Chemical composition data. Energy level alignment and band bending data. Photovoltaic characteristics data.
Characterization Technics: LabXPS and synchrotron-based HAXPES for chemical analysis. Characterization of interface solar cell characteristics and operational stability.
Characterization Data Type: XPS spectra data (chemical composition at the interface). HAXPES data for depth profiling and understanding interface chemistry.
Analyzed Data: Analysis of the emergence of new chemical species at the interface due to the ALD process. Assessment of the impact of PTAA interlayer on interface chemistry and solar cell performance. Identification of stoichiometric changes and defect formation at the MHP/ALD-NiOx interface.
Main Targets Project: To study the interface formation between metal halide perovskites and ALD oxide films. To understand the chemical and physical interactions at the interface and their impact on solar cell performance.
Main Achievements Findings: Direct observation of new chemical species emergence at the interfaces. Noted mitigation of interface reactions by using a PTAA interlayer. Identification of detrimental hydroxide and oxy-hydroxide species at the MHP/ALD-NiOx interface. Improved performance and operational stability of perovskite solar cells with optimized interfaces.
Review 22
How would you describe your experience with the VIPERLAB opportunity? How did the experience/visit at the HiKE beamline meet your expectations?
We had a perfect experience at the HiKE beamline that fully met our expectations. Due to the well established measurement protocols and assistance we were able to even exceed our initial measurement plan.
Did you face any difficulties during your visit or application process?
The application process went smooth and without any complications. As a more general remark, we are presently looking into opportunities on how different techniques from the catalogue at the various institutes could be combined into one larger project.
Does this VIPERLAB experience at the HiKE beamline bring you closer to your research objectives? How?
The experiment performed in the framework of our Viperlab proposal proved to be absolutely essential to our research goals. We were able to acquire the decisive data points for the two chapters of the PhD thesis of our graduate student, Nitin Mallik, who joined for the beam time.
What other VIPERLAB activities have you participated in, or would you like to participate in?
We would like to further engage in a coordinated synthesis and measurement series with the HySprint platform and further beam times at BESSY. The goal of this endeavour is to combine our own synthesis and advanced characterization approach to aid in the community effort of reliably screening possible new photoabsorber compositions.
Do you intend or already did publish/present your collected results in a paper or conference?
We will present the data from the beam time in a talk at the RAFALD conference and we are confident that the data is sufficient to publish one paper (NiO on perovskite and organic buffer layer) and lay the basis for a second paper (NiO on a MeO2PACz interlayer).