p-Doping of organic semiconductors for stable and efficient perovskite solar cells
Solution-processed perovskites enabled high efficiency photovoltaic cells. In these devices, organic semiconductors (OSCs, e.g., spiroOMeTAD, PTAA) are used as charge transport layers. To this end, stable and efficient molecular dopants have been developed to improve the efficiency as well the environmental stability of perovskites solar cells. In this project, we seek to develop Lewis acid doped hole transporting layers by using a suite of wet-lab facilities and characterization techniques at IMEC(Belgium) to gain insights into the morphology-stability-property relationships. In addition, we will correlate these findings with the structural analysis obtained from solid-state NMR and EPR spectroscopy (experiments will be carried out at Lille University, France), and hence provide insights into doping mechanisms and efficiencies of contact layers in perovskites solar cells.
Status: Ongoing
Date of proposal: 30/08/2022
Start date: 02/11/2022
End Date: 09/11/2022
Used Instruments: Not specified in detail but likely includes tools for thin film preparation and characterization, such as spin-coaters, annealing ovens, and measurement systems for electrical and morphological characterization.
Experimental Technique: Preparation of p-doped Spiro-OMeTAD using Lewis-acid tris(pentafluorophenyl)borane (BCF). Morphological characterization of thin films. Solid-state NMR and EPR spectroscopy for structural analysis.
Experiment Description: The project was focused on preparing p-doped Spiro-OMeTAD using BCF semiconductor ink and thin films. The main goal was to characterize the morphology and film thickness at IMEC (EnergyVille2) and correlate these findings with structural analysis obtained from solid-state NMR and EPR spectroscopy.
Type Samples: Spiro-OMeTAD:BCF thin films.
Sample Description: Thin films prepared by doping Spiro-OMeTAD with BCF, coated on ITO-coated glass substrates.
Experiment Data Type: Morphological features of the thin films Solid-state NMR spectroscopy results (1H and 11B). Moisture stability data of Spiro-OMeTAD upon p-doping.
Characterization Technics: Morphological analysis using microscopy. Solid-state NMR and EPR spectroscopy for structural and electronic analysis.
Characterization Data Type: Morphology and film thickness. Structural analysis using NMR and EPR data. Stability aspects in relation to moisture.
Analyzed Data: Improved thin film morphology due to enhanced solubility and polarity of BCF dopants. Solid-state NMR spectroscopy corroborating morphological results. Increased moisture stability of Spiro-OMeTAD upon p-doping with BCF.
Main Targets Project: To prepare and characterize p-doped Spiro-OMeTAD for perovskite solar cells. To understand the doping mechanisms and efficiencies of contact layers in perovskite solar cells.
Main Achievements Findings: Successful preparation of Lewis acid p-doped Spiro-OMeTAD:BCF thin films. Morphological improvement of thin films with BCF doping. Enhanced moisture stability of Spiro-OMeTAD upon p-doping. Detailed understanding of stability aspects and structural analysis through solid-state NMR and EPR spectroscopy.