Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance ...Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance for the colloidal stability and property tuning of PQDs, while their highly dynamic binding nature not only impedes further efficiency improvement of PQD-based solar cells but also induces intrinsic instability. Tremendous efforts have been made in ligand engineering with good hopes to solve such challenging issues in the past few years. In this review, we first present a fundamental understanding of the role of surface ligands in PQDs, followed by a brief discussion and classification of various ligands that have the potential for improving the electronic coupling and stability of PQD solids. We then provide a critical overview of recent advances in ligand engineering including the strategies of in-situ ligand engineering, postsynthesis/-deposition ligand-exchange, and interfacial engineering, and discuss their impacts on changing the efficiency and stability of perovskite QD solar cells(QDSCs). Finally, we give our perspectives on the future directions of ligand engineering towards more efficient and stable perovskite QDSCs.展开更多
In recent years, significant attention has been paid to perovskite materials. In particular, lead triiodide-based perovskites have exhibited superb optoelectronic properties. Enhancing the stability of these materials...In recent years, significant attention has been paid to perovskite materials. In particular, lead triiodide-based perovskites have exhibited superb optoelectronic properties. Enhancing the stability of these materials is an essential step towards large-scale applications. In this stud） by simply adding trioctylphosphine （TOP） as part of the post-synthesis treatment, we significantly enhance the stability of CsPbI3 quantum dots （QDs） in the solution phase, which otherwise decay rapidly in hours. For CsPbI3 QDs treated with TOP, the absorption and photoluminescence emission properties are unchanged over the course of weeks, and the quantum yield remains almost constant at 30% even after 1 month. The morphologies of both treated and untreated QDs are initially cubic; however, the treated QDs largely maintain their initial size and shape, while the untreated ones lose size uniformity, which is a sign of degradation. Infrared spectroscopy and X-ray photoelectron spectroscopy confirm the presence of P in the TOP-treated QDs. We hope that the technique of utilizing a ligand post-treatment will lead to new insights that help to resolve the intrinsic instability issue of triiodide perovskite materials and devices.展开更多
All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their sup...All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.展开更多
基金the financial support from the Australian Research Council (ARC) Laureate Fellowship (FL190100139)the ARC Discovery Project (DP200101900)+3 种基金the CRC-P programsthe funding support from the ARC through Discovery Early Career Researcher Award Fellowship (DE190101351)the Discovery Project (DP190102507)the financial support from University of Queensland Research Training Scholarship。
文摘Lead halide perovskite quantum dots(PQDs) have recently emerged as promising light absorbers for photovoltaic application due to their extraordinary optoelectronic properties. Surface ligands are of utmost importance for the colloidal stability and property tuning of PQDs, while their highly dynamic binding nature not only impedes further efficiency improvement of PQD-based solar cells but also induces intrinsic instability. Tremendous efforts have been made in ligand engineering with good hopes to solve such challenging issues in the past few years. In this review, we first present a fundamental understanding of the role of surface ligands in PQDs, followed by a brief discussion and classification of various ligands that have the potential for improving the electronic coupling and stability of PQD solids. We then provide a critical overview of recent advances in ligand engineering including the strategies of in-situ ligand engineering, postsynthesis/-deposition ligand-exchange, and interfacial engineering, and discuss their impacts on changing the efficiency and stability of perovskite QD solar cells(QDSCs). Finally, we give our perspectives on the future directions of ligand engineering towards more efficient and stable perovskite QDSCs.
文摘In recent years, significant attention has been paid to perovskite materials. In particular, lead triiodide-based perovskites have exhibited superb optoelectronic properties. Enhancing the stability of these materials is an essential step towards large-scale applications. In this stud） by simply adding trioctylphosphine （TOP） as part of the post-synthesis treatment, we significantly enhance the stability of CsPbI3 quantum dots （QDs） in the solution phase, which otherwise decay rapidly in hours. For CsPbI3 QDs treated with TOP, the absorption and photoluminescence emission properties are unchanged over the course of weeks, and the quantum yield remains almost constant at 30% even after 1 month. The morphologies of both treated and untreated QDs are initially cubic; however, the treated QDs largely maintain their initial size and shape, while the untreated ones lose size uniformity, which is a sign of degradation. Infrared spectroscopy and X-ray photoelectron spectroscopy confirm the presence of P in the TOP-treated QDs. We hope that the technique of utilizing a ligand post-treatment will lead to new insights that help to resolve the intrinsic instability issue of triiodide perovskite materials and devices.
基金National Natural Science Foundation of China (No. 21771063)State Key Research Development Program of China (No. 2016YFA0204200)Fundamental Research Funds for the Central Universities in China (Nos. WJ1714046 and 222201717003).
文摘All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.
