Periodic Reporting for period 1 - STARS (STable perovskite solar cells via interfacial engineering of 2D/3D mixed-dimensional Absorbers and Robust dopant-free hole transporting materialS)
Período documentado: 2019-09-01 hasta 2021-08-31
Metal halide perovskites (MAPbI3 or FAPbI3 where MA= methylammonium, FA= formamidinium) have emerged as wonder materials for optoelectronic devices. In particular, the progress in photovoltaic (PV) devices based on these hybrid perovskite materials has been unprecedented. This rapid progress acquires great importance in the view of the commitment of the EU to move towards a low-carbon society by 2050. Solar energy harvesting is considered the leading solution in the renewable energy sector since it is low-cost, effective, sustainable, and green. Hybrid perovskite PV is a promising solar cell technology with power conversion efficiency (PCE) emerging from 3.8% in its first study to a current, certified value of 25.5% in single-junction perovskite solar cells (PSCs). In light of low manufacturing costs and appealing device performance, the levelized cost of electricity (LCOE) of perovskite PVs has the potential to reach impressively low levels to drive the global energy transition economically. However, despite the promises, the commercialization of PSCs is impeded by the low device stability. The poor device stability primarily stems from the intrinsic material chemistry, which leads to the formation of defects and mobile ions. Such mobile ions can diffuse into the interfaces, causing catastrophic failure. Furthermore, the hole transporting material employed for high-efficiency PSCs requires doping with ionic additives that are hydrophilic, and they lower the glass transition temperature, thus compromising the moisture and thermal stability, respectively.
The objective of this project (STARS) was to tackle these stability issues by developing new robust perovskite absorbers combined with more stable, dopant-free hole-transporting materials (HTM). Apart from the scientific objectives, fostering the development of the fellow is also one of the project's key objectives. This project aligns with EU goals to replace traditional fossil fuels with renewable energy sources, significantly reducing the global carbon footprint and curbing anthropogenic CO2 emissions. Overall, this project is vital since it focuses on research on materials for a sustainable future to benefit society by improving human life quality, generating fundamental knowledge, and yielding robust technologies.
The STARS project has succeeded in developing strategies for the bulk and interface engineering along with the development of HTMs, which has led to highly efficient (>24 %) and stable PSCs with T80 > 6000 h (time at which device loss 80% of the initial performance). The project has also succeeded in the career development of the fellow.
The objective of this project (STARS) was to tackle these stability issues by developing new robust perovskite absorbers combined with more stable, dopant-free hole-transporting materials (HTM). Apart from the scientific objectives, fostering the development of the fellow is also one of the project's key objectives. This project aligns with EU goals to replace traditional fossil fuels with renewable energy sources, significantly reducing the global carbon footprint and curbing anthropogenic CO2 emissions. Overall, this project is vital since it focuses on research on materials for a sustainable future to benefit society by improving human life quality, generating fundamental knowledge, and yielding robust technologies.
The STARS project has succeeded in developing strategies for the bulk and interface engineering along with the development of HTMs, which has led to highly efficient (>24 %) and stable PSCs with T80 > 6000 h (time at which device loss 80% of the initial performance). The project has also succeeded in the career development of the fellow.
The project results were in line with the proposed objectives, milestones, and deliverables. The work performed within this project included (a) rational molecular design and synthesis of the bulk and surface passivation materials for the development of robust absorber; (b) molecular design and synthesis of dopant free HTMs; (c) Structural, morphological and optoelectronic characterization of the developed absorbers at different length scale (several µm to few nm); (d) Structural, optoelectronic and electrochemical characterization of HTMs; (e) Device fabrication with the developed absorbers and HTMs (f) rigorous stability evaluation under different condition (moisture, heat, electric field, etc..) of the fabricated devices. (g) establishing structure-property relationships. This project has led to several key results and findings, some of which have been published in top peer-reviewed journals, and several manuscripts are under preparation.
Our work titled: Our work titled: Nanoscale interfacial engineering enables highly stable and efficient perovskite photovoltaics (Energy Environ. Sci., 2021,14, 5552-5562, Impact factor = 38.5) has been a breakthrough study on molecular engineering of the interface in PSCs. In this study, we developed a facile molecular-level interface engineering strategy using a multifunctional ligand, which augments the stability of single-junction solar cells. The results of the work offer recommendations to expedite the design strategies of passivating ligands and are expected to stimulate further work on the fundamental understanding of interfacial ion diffusion mechanisms to facilitate stable and efficient PSCs. In this study's follow-up, we have designed a series of interface materials, leading to a high PCE of 24 % and excellent long-term stability. Using multiscale characterization and modeling techniques, we establish the correlation between the molecular design, interaction and the interface defects, and interfacial ion diffusion. So far, there is no clear understanding of interface ion diffusion; thus, this work is expected to improve its understanding. Currently, this manuscript is under preparation.
In another study, we develop a facile 2D/3D interface engineering strategy using supramolecular chemistry. This approach has led to PSCs with a PCE of > 24 % with excellent long-term operational stability. Further, we employ solid-state nuclear magnetic resonance (ss-NMR), photoluminescence, and scanning tunneling spectroscopy to unravel critical insights of the 2D/3D interface. Currently, this manuscript is under preparation.
We also have developed two new HTMs. The devices fabricated using these HTMs show better performance and stability than those fabricated from classical HTM (Spiro-OMeTAD). Currently, the manuscript is in preparation. Apart from journal publications, results and findings were presented in several top conferences and media outlets.
Our work titled: Our work titled: Nanoscale interfacial engineering enables highly stable and efficient perovskite photovoltaics (Energy Environ. Sci., 2021,14, 5552-5562, Impact factor = 38.5) has been a breakthrough study on molecular engineering of the interface in PSCs. In this study, we developed a facile molecular-level interface engineering strategy using a multifunctional ligand, which augments the stability of single-junction solar cells. The results of the work offer recommendations to expedite the design strategies of passivating ligands and are expected to stimulate further work on the fundamental understanding of interfacial ion diffusion mechanisms to facilitate stable and efficient PSCs. In this study's follow-up, we have designed a series of interface materials, leading to a high PCE of 24 % and excellent long-term stability. Using multiscale characterization and modeling techniques, we establish the correlation between the molecular design, interaction and the interface defects, and interfacial ion diffusion. So far, there is no clear understanding of interface ion diffusion; thus, this work is expected to improve its understanding. Currently, this manuscript is under preparation.
In another study, we develop a facile 2D/3D interface engineering strategy using supramolecular chemistry. This approach has led to PSCs with a PCE of > 24 % with excellent long-term operational stability. Further, we employ solid-state nuclear magnetic resonance (ss-NMR), photoluminescence, and scanning tunneling spectroscopy to unravel critical insights of the 2D/3D interface. Currently, this manuscript is under preparation.
We also have developed two new HTMs. The devices fabricated using these HTMs show better performance and stability than those fabricated from classical HTM (Spiro-OMeTAD). Currently, the manuscript is in preparation. Apart from journal publications, results and findings were presented in several top conferences and media outlets.
This project has tackled the stability challenge of the PSCs. It shows progress beyond the state-of-the-art in several aspects such as molecular design strategy, performance, long-term operational stability, and fundamental knowledge on the active layer and interfaces. One of the most significant breakthroughs is understanding the role of the perovskite/charge transporting layer (CTL) interface towards achieving long-term stability. This project will improve the scientific and technological knowledge needed for various optoelectronic devices based on hybrid perovskite materials. It has generated knowledge critical for further innovations in the research field and the development of high-performance and stable hybrid organic-inorganic perovskite technology. The molecular design developed in this project will benefit a wide array of applications. This project brings PSCs one step closer to commercialization, stimulating economic growth, generating jobs, and supporting the EU goals of reducing the carbon footprint.