Unveiling defect-strain relationships in halide perovskite solar cells through modelling-experiment combinations
Lead Research Organisation:
University of Cambridge
Department Name: Chemical Engineering and Biotechnology
Abstract
Recently, European Commission announced a set of policy initiatives called European Green Deal which aims at net zero greenhouse gases in Europe by 2050, and photovoltaic technologies are expected to play a significant role in sustainable energy generation. Although halide perovskites have been highlighted as a class of the most promising materials for solar cells due to a combination of low-cost solution processibility and high power conversion efficiency, non-radiative losses and chemical decomposition originated from defects in the perovskite films prevent them from being commercialised successfully. The primary goal of this project is to unveil defect-strain relationships and to provide a way to exploit as an extra lever for defect control. To attain the goal, how microscopic structural changes at halide perovskite lattice sites affect performance of macroscopic solar cells needs to be understood, which cannot be done from a single research technique. A multidisciplinary approach - various spectroscopy and microscopy measurements as stepping stones in between the two end points - is, thus, an essential part of this ambitiously proposed project. The applicant (Dr Young-Kwang Jung) will perform state-of-the-art first-principles materials simulation techniques to identify responses of (i) native point defects; (ii) extrinsic dopants; and (iii) extended defects to lattice strain in halide perovskite solar cells, which will be complemented by cutting edge experimental validation from the host (Dr Samuel D. Stranks and the StraksLab at the University of Cambridge). The results of this project will provide practical solutions to improve the device efficiency and stability, which will accelerate commercialisation of halide perovskite solar cells in the public market. Consequently, this work will contribute the world-wide movement for zero-carbon energy generation, and ultimately, will alleviate the global warming.
Publications
Iqbal AN
(2024)
Composition Dictates Octahedral Tilt and Photostability in Halide Perovskites.
in Advanced materials (Deerfield Beach, Fla.)
Kim Y
(2024)
Reversible Oxidative p-Doping in 2D Tin Halide Perovskite Field-Effect Transistors
in ACS Energy Letters
Park J
(2023)
Metal Halide Thermoelectrics: Prediction of High-Performance Cs Cu 2 I 3
in PRX Energy
Yu Z
(2023)
Hydrogen Bond-Assisted Dual Passivation for Blue Perovskite Light-Emitting Diodes
in ACS Energy Letters
| Description | Throughout the investigation spanning the award period to date, we significantly advanced our understanding of defect-strain relationships in halide perovskites. Firstly, we conducted state-of-the-art simulations of native point defects in halide perovskites under both compressive and tensile strain conditions. Utilising supercell models that contains hundreds of atoms, we calculated the changes in trap levels and concentrations of native defects in halide perovskites. This analysis will offer valuable guidelines for strain engineering in the development of high-performance perovskite solar cells. Secondly, we developed a unique model to elucidate the role of interfacial effects triggered by local tilting of octahedral networks in halide perovskites. Our model allowed us to reveal charge carrier blocking behaviors and strain induced by the formation of interfacial defects. Third, we have expanded the project to include interfaces between 2-dimensional (2D) and 3-dimensional (3D) halide perovskites. It was found that the local arrangement of ions and ligands at these interfaces affects inter-layer spacing, and more importantly determines how charge carriers transport through these interfaces. These findings will boost the optimisation of perovskite solar cell and LED devices for higher efficiency and longer stability. These results highlight the importance of a fundamental understanding of local structures for the development of perovskite-based optoelectronic devices. Our key findings align closely with the objectives of the proposed research projects. |
| Exploitation Route | The tools and findings will be useful for the wider academic community working on these materials, as well as emerging industry. |
| Sectors | Chemicals Electronics Energy |
| Description | Theory-experiment collaboration with Prof. Bo Ram Lee's group at Sungkyunkwan University in South Korea |
| Organisation | Sungkyunkwan University |
| Country | Korea, Republic of |
| Sector | Academic/University |
| PI Contribution | We performed density functional calculations to understand the interactions between dual-passivation additive diphenylphosphinamide (DPPA) and surfaces of halide perovskites |
| Collaborator Contribution | Prof. Bo Ram Lee's group at Sungkyunkwan University (SKKU) in South Korea incorporated dual-passivation additive diphenylphosphinamide (DPPA) into perovskite films, and fabricated perovskite based light-emitting diodes which achieved an external quantum efficiency of 12.31%. |
| Impact | Publication in ACS Energy Letters, which is one of the most impactful journals in the field energy materials. (DOI:10.1021/acsenergylett.3c01323) |
| Start Year | 2022 |
| Description | Theory-experiment collaboration with Prof. Takhee Lee's group and Prof. Keehoon Kang's group at Seoul National University in South Korea |
| Organisation | Seoul National University |
| Country | Korea, Republic of |
| Sector | Academic/University |
| PI Contribution | We have performed density functional calculations to provide atomistic understanding of the interaction between oxygen molecule induced defects and two-dimensional perovskite's lattice. |
| Collaborator Contribution | Prof. Takhee Lee's group and Prof. Keehoon Kang's group at Seoul National University (SNU) in South Korea have fabricated two-dimensional halide perovskite-based field-effect transistors that exhibit reversible p-doping behaviour. They conducted experimental characterizations to understand the impact of operating conditions on their reversibility and found oxygen molecules play an important role in the reversible p-doping behaviour. |
| Impact | A manuscript based on this collaboration is just accepted for its publication in ACS Energy Letters, which is one of the most impactful journals in the field energy materials. (No DOI issued yet, title: Reversible oxidative p-doping in 2D tin halide perovskite field-effect transistors) |
| Start Year | 2022 |
| Description | Oral presentation at European Materials Research Society (EMRS) 2023 Spring Meeting |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | I participated in European Materials Research Society Fall Meeting (the largest conference in the field of materials research in Europe) where thousands of international researchers were attended, and gave an oral presentation on electronic consequences of local tilting in halide perovskites. This is an emerging topic in the perovskite solar cells and LEDs communities and my presentation reported electronic structure of local tilting layers in the material for the first time, which have researchers recognise the importance of understanding local structures in halide perovskites. |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://www.european-mrs.com/meetings/archives/2023/2023-spring-meeting |
| Description | Oral presentation at The Materials for Sustainable Development Conference (MATSUS24) |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | I participated in The Materials for Sustainable Development Conference where hundreds of international researchers were attended, and gave an oral presentation about influence of atomic configurations on physical/chemical properties at 2D/3D halide perovskite interfaces, which is a crucial topic for the perovskite solar cells and LEDs communities. My presentation offered experimental researchers working on device fabrication fundamental insights into how local atomic configurations at interfaces can govern the overall properties of heterojunctions. |
| Year(s) Of Engagement Activity | 2024 |
| URL | https://www.nanoge.org/MATSUS24/home |
| Description | Poster presentation at 2022 Materials Research Society (MRS) Fall Meeting & Exhibition |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | I participated in Materials Research Society Fall Meeting (the largest conference in the field of materials research in the world) where thousands of international researchers were attended, and gave a poster presentation on n-type doping for metal halide compounds. Many fruitful discussion were made, which allowed me to improve scientific impact of my research project and allowed other researchers to think of efficient doping method for those materials. |
| Year(s) Of Engagement Activity | 2022 |
| URL | https://www.mrs.org/meetings-events/fall-meetings-exhibits/2022-mrs-fall-meeting/symposium-sessions |
| Description | Poster presentation at 2023 Materials Research Society (MRS) Fall Meeting & Exhibition |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Postgraduate students |
| Results and Impact | I participated in Materials Research Society Fall Meeting (the largest conference in the field of materials research in the world) where thousands of international researchers were attended, and gave a poster presentation on structure-property relationships in 2D/3D halide perovskite heterojunctions. Since this topic is currently one of the most popular in the perovskite solar cells and LEDs communities, my presentation attracted significant attention, and led many researchers to consider how we can further optimise device architectures for optoelectronic applications. |
| Year(s) Of Engagement Activity | 2023 |
| URL | https://www.mrs.org/meetings-events/fall-meetings-exhibits/2023-mrs-fall-meeting |