Periodic Reporting for period 1 - Fullerene_PSC (Elucidating fullerene-perovskite interactions by means of First-principles calculations: Towards a rational design of low cost solar cells)
Reporting period: 2022-07-01 to 2024-06-30
Perovskite solar cells (PSCs) have emerged as a highly promising technology due to the necessity of efficient, cost-effective, and sustainable energy solutions. PSCs faces significant challenges that hinder their commercialization and long-term stability. One of the main issues is the presence of defects and trap states within the perovskite material, which can drastically reduce the efficiency and stability of the solar cells.
A critical aspect of improving PSCs involves the integration of fullerene derivatives, which have shown potential in passivating surface defects and suppressing trap states. However, the detailed mechanisms by which fullerenes achieve these effects were not well understood before our project.
Importance for Society:
Addressing the challenges in PSCs is crucial for advancing renewable energy technologies and supporting global efforts to transition away from fossil fuels. Enhanced PSCs could provide a low-cost, high-efficiency solution for solar energy, contributing to energy sustainability and reducing greenhouse gas emissions.
Overall Objectives:
The Fullerene_PSC project used supercomputers to accelerate the rational design of fullerene derivatives. Our specific objectives were aligned with addressing the key challenges in PSC and advancing the state-of-the-art understanding of fullerene-perovskite interactions. The project’s main objectives included:
o We aimed to explore the adsorption modes, binding energies, and electronic properties of fullerenes on perovskite surfaces, particularly focusing on systems with defects.
o A key goal was to understand charge transfer processes between perovskite materials and fullerenes.
o The project sought to establish descriptors and scaling relations that correlate computational findings with experimental parameters.
Conclusions of the Action:
The Fullerene_PSC project has unveiled critical mechanisms by which fullerenes interact with and passivate defects in perovskite materials. We discovered that fullerene adsorption on perovskite surfaces, especially those with iodine (I) antisite defects, induces surface reconstruction that effectively eliminates trap states. This reconstruction is essential for stabilizing the perovskite material and enhancing its electronic properties.
A critical aspect of improving PSCs involves the integration of fullerene derivatives, which have shown potential in passivating surface defects and suppressing trap states. However, the detailed mechanisms by which fullerenes achieve these effects were not well understood before our project.
Importance for Society:
Addressing the challenges in PSCs is crucial for advancing renewable energy technologies and supporting global efforts to transition away from fossil fuels. Enhanced PSCs could provide a low-cost, high-efficiency solution for solar energy, contributing to energy sustainability and reducing greenhouse gas emissions.
Overall Objectives:
The Fullerene_PSC project used supercomputers to accelerate the rational design of fullerene derivatives. Our specific objectives were aligned with addressing the key challenges in PSC and advancing the state-of-the-art understanding of fullerene-perovskite interactions. The project’s main objectives included:
o We aimed to explore the adsorption modes, binding energies, and electronic properties of fullerenes on perovskite surfaces, particularly focusing on systems with defects.
o A key goal was to understand charge transfer processes between perovskite materials and fullerenes.
o The project sought to establish descriptors and scaling relations that correlate computational findings with experimental parameters.
Conclusions of the Action:
The Fullerene_PSC project has unveiled critical mechanisms by which fullerenes interact with and passivate defects in perovskite materials. We discovered that fullerene adsorption on perovskite surfaces, especially those with iodine (I) antisite defects, induces surface reconstruction that effectively eliminates trap states. This reconstruction is essential for stabilizing the perovskite material and enhancing its electronic properties.
In Fullerene_PSC project, we have used computational resources provided by EuroHPC and Red Española de Supercomputación for understanding the fullerene-perovskite interactions and improve the design of fullerene derivatives for enhanced performance in PSCs.
• We began by performing detailed periodic boundary condition calculations using VASP to model the adsorption of various fullerenes. These calculations were designed to uncover the adsorption modes and binding energies of these fullerenes on pristine and defective perovskite surfaces.
• We extended our analysis to surfaces with common defects, such as Cs/MA vacancies (surface charge of -1), Pb vacancies (-2), and I antisites (-3). These studies revealed significant variations in the adsorption behavior and electronic properties of the fullerenes depending on the type and presence of these defects. We discovered that fullerenes preferentially orient themselves to maximize contact with the surface, particularly on defective perovskites surfaces.
• Recognizing the limitations of molecular models, we shifted back to periodic boundary condition calculations with charged surfaces. This approach provided a more accurate representation of the charge transfer dynamics.
• Considering all the data generated for several fullerenes in Cs and MA lead perovskite surfaces, we began analyzing the data to identify key descriptors that correlate computational findings with experimental parameters.
Main Results Achieved:
o We identified that the adsorption of fullerenes on perovskite surfaces presents attractive binding energies where the lowest energy adsorption sites imply to maximize the number of fullerene-perovskite contacts.
o I antisite defects induces significant surface reconstruction. The presence of I-I-I moieties implies surface reconstruction with the subsequent formation of trap states, which may affect the solar cell performance.
o The adsorption of fullerenes eliminates trap states by promoting the surface reconstruction. The reconstructed surfaces do not show trap states anymore. This new reconstructed surfaces are higher in energy compared to the lowest energy surface configuration with trap states which means that only appear stable when fullerenes are adsorbed, unveiling a critical mechanism for passivating trap states.
Exploitation and Dissemination of Results:
• Scientific Publications and Conferences: The project’s findings have been disseminated through a series of scientific publications and presentations at international conferences. For the moment, one publication can be consulted (10.1002/chem.202401283) and many more are in preparation. Our work has been disseminated in catalan, Spanish, and international conferences like ACS fall 2023 and 244th ECS. Moreover, I was invited to EuroHPC conference in 2023 to disseminate the work carried out.
• Open Access Data: All computational data, including energies and structural models, have been made available through open access repositories (NOMAD) or supplementary materials in our publications.
• Future Directions: Given the promising results and the wealth of data generated, the project will continue to explore new fullerene derivatives and further refine the understanding of their interactions with perovskites.
• We began by performing detailed periodic boundary condition calculations using VASP to model the adsorption of various fullerenes. These calculations were designed to uncover the adsorption modes and binding energies of these fullerenes on pristine and defective perovskite surfaces.
• We extended our analysis to surfaces with common defects, such as Cs/MA vacancies (surface charge of -1), Pb vacancies (-2), and I antisites (-3). These studies revealed significant variations in the adsorption behavior and electronic properties of the fullerenes depending on the type and presence of these defects. We discovered that fullerenes preferentially orient themselves to maximize contact with the surface, particularly on defective perovskites surfaces.
• Recognizing the limitations of molecular models, we shifted back to periodic boundary condition calculations with charged surfaces. This approach provided a more accurate representation of the charge transfer dynamics.
• Considering all the data generated for several fullerenes in Cs and MA lead perovskite surfaces, we began analyzing the data to identify key descriptors that correlate computational findings with experimental parameters.
Main Results Achieved:
o We identified that the adsorption of fullerenes on perovskite surfaces presents attractive binding energies where the lowest energy adsorption sites imply to maximize the number of fullerene-perovskite contacts.
o I antisite defects induces significant surface reconstruction. The presence of I-I-I moieties implies surface reconstruction with the subsequent formation of trap states, which may affect the solar cell performance.
o The adsorption of fullerenes eliminates trap states by promoting the surface reconstruction. The reconstructed surfaces do not show trap states anymore. This new reconstructed surfaces are higher in energy compared to the lowest energy surface configuration with trap states which means that only appear stable when fullerenes are adsorbed, unveiling a critical mechanism for passivating trap states.
Exploitation and Dissemination of Results:
• Scientific Publications and Conferences: The project’s findings have been disseminated through a series of scientific publications and presentations at international conferences. For the moment, one publication can be consulted (10.1002/chem.202401283) and many more are in preparation. Our work has been disseminated in catalan, Spanish, and international conferences like ACS fall 2023 and 244th ECS. Moreover, I was invited to EuroHPC conference in 2023 to disseminate the work carried out.
• Open Access Data: All computational data, including energies and structural models, have been made available through open access repositories (NOMAD) or supplementary materials in our publications.
• Future Directions: Given the promising results and the wealth of data generated, the project will continue to explore new fullerene derivatives and further refine the understanding of their interactions with perovskites.
Before the Fullerene_PSC project, the role of fullerenes in passivating surface defects and suppressing trap states in perovskite solar cells (PSCs) was not thoroughly understood.
o We discovered that fullerenes can induce surface reconstruction on perovskite surfaces, especially those with iodine antisite defects. This reconstruction is a novel mechanism by which trap states are eliminated, thus enhancing the efficiency of PSCs. Our findings reveal that this transformation is energetically favorable only in the presence of adsorbed fullerenes.
o Calculations have shown that the adsorption of fullerenes on perovskite surfaces, whether pristine or defective, prioritizes maximizing contact points, leading to unique binding configurations. This comprehensive analysis has elucidated how different surface defects, such as Cs/MA vacancies, Pb vacancies, and I antisites, affect the binding energies and orientations of fullerenes.
Expected Results Until the End of the Project:
o We expect to find suitable descriptors to predict new fullerene-PSC systems. This will involve synthesizing and characterizing new fullerene derivatives and comparing their performance against our theoretical models.
o Additional scientific papers will be published, detailing the final results of our studies on fullerene-perovskite interactions and charge transfer dynamics.
Socio-Economic Impact:
o By enhancing the efficiency and stability of PSCs through a deeper understanding of fullerene interactions, this project contributes directly to the development of more effective solar energy solutions, in agreement with Agenda 2030.
o Improved PSC technologies contribute to environmental sustainability by providing cleaner, more efficient energy alternatives. This helps reduce greenhouse gas emissions and mitigates the impact of climate change, fostering a healthier planet for future generations.
o We discovered that fullerenes can induce surface reconstruction on perovskite surfaces, especially those with iodine antisite defects. This reconstruction is a novel mechanism by which trap states are eliminated, thus enhancing the efficiency of PSCs. Our findings reveal that this transformation is energetically favorable only in the presence of adsorbed fullerenes.
o Calculations have shown that the adsorption of fullerenes on perovskite surfaces, whether pristine or defective, prioritizes maximizing contact points, leading to unique binding configurations. This comprehensive analysis has elucidated how different surface defects, such as Cs/MA vacancies, Pb vacancies, and I antisites, affect the binding energies and orientations of fullerenes.
Expected Results Until the End of the Project:
o We expect to find suitable descriptors to predict new fullerene-PSC systems. This will involve synthesizing and characterizing new fullerene derivatives and comparing their performance against our theoretical models.
o Additional scientific papers will be published, detailing the final results of our studies on fullerene-perovskite interactions and charge transfer dynamics.
Socio-Economic Impact:
o By enhancing the efficiency and stability of PSCs through a deeper understanding of fullerene interactions, this project contributes directly to the development of more effective solar energy solutions, in agreement with Agenda 2030.
o Improved PSC technologies contribute to environmental sustainability by providing cleaner, more efficient energy alternatives. This helps reduce greenhouse gas emissions and mitigates the impact of climate change, fostering a healthier planet for future generations.