Periodic Reporting for period 2 - SENSATE (Low dimensional semiconductors for optically tuneable solar harvesters)
Berichtszeitraum: 2021-12-01 bis 2023-05-31
SENSATE proposes ground-breaking ideas and concepts for the development of novel materials with exotic optic and electric properties, that can be the solution for a semi-transparent or transparent and universal solar energy harvester. The project is developing disruptive materials based on mixed chalcogen and halogen compounds, that can easily adopt tunable micro-columnar morphology, which optoelectronic properties strongly depend on their orientation. The synthesis of this type of compounds was extremely complicate until now, and SENSATE introduces new methodologies based on the use of high-pressure thermal treatment, succeeding to synthesize for the first time several of these complex compounds.
The availability of this new type of technologies using this mixed chalcogen-halogen compounds, can have a strong societal impact, providing among others more efficient, robust, and versatile solar energy generators for transparent, semi-transparent, and colored devices for advanced BIPV applications and electronics. In addition, these excellent light-absorbing materials, thanks to the peculiar micro-columnar morphology can offer also very relevant perspectives for the development of very high active area photocatalyst, for hydrogen production or pollutants degradation.
With this in mind, the final aim of SENSATE is to develop a new class of very versatile materials and devices, that can have a strong impact in our ways to manage the light-to-electricity conversion, towards the discovery of semiconductors which optic and electric properties can be controlled through the chemical-structure manipulation, but also through their morphology management.
The availability of this new type of technologies using this mixed chalcogen-halogen compounds, can have a strong societal impact, providing among others more efficient, robust, and versatile solar energy generators for transparent, semi-transparent, and colored devices for advanced BIPV applications and electronics. In addition, these excellent light-absorbing materials, thanks to the peculiar micro-columnar morphology can offer also very relevant perspectives for the development of very high active area photocatalyst, for hydrogen production or pollutants degradation.
With this in mind, the final aim of SENSATE is to develop a new class of very versatile materials and devices, that can have a strong impact in our ways to manage the light-to-electricity conversion, towards the discovery of semiconductors which optic and electric properties can be controlled through the chemical-structure manipulation, but also through their morphology management.
The scientific/technologic activities of SENSATE are divided into 4 complementary work packages. In the first workpackage, new materials and devices are modeled using advanced computational tools and machine learning concepts. In particular, the new class of chalco-halide compounds were modeled using density-functional-theory (DFT) calculations allowing to have a map of most relevant structural, optical and electrical properties of these materials. In addition, the combination of DFT with machine learning tools for the first time is expanding the capabilities of modelling of materials, thanks to the possibility to predict the properties of solid solution alloys in the complete composition range. Complementary, a baseline for device modeling was built and tested for different solar cell configurations, and the high potential of these materials for photovoltaic conversion demonstrated theoretically.
In the second workpackage, a complete screeing of electron and hole selective contacts was performed, defining the most suited devices architectures for the new materials under development. Deep surface analysis and chemical modification was performed, in order to manage the surface properties for interfaces optimization. On the other hand, a new type of conjugated electrolytes with fractal geometry have been developed as dipolar molecules for enhancing contact selectivity, and demonstrated for the first time in an emerging thin film technology.
In the third workpackage, a new methodology for the synthesis of complex van der Waals chalco-halide compounds was developed, based on the coevaporation of a chalcogenide compound a followed by a high pressure annealing. A completely new family of compounds including SbSI, SbSeI, SbSBr, SbSeBr, BiSI, BiSeI, BiSBr and BiSeBr were synthesized, and their quasi-one-dimensional structure demonstrated. Fundamental properties of these new type of materials were investigated through a complete advanced characterization, and the different possible applications of each of them was analysied.
Finally, in the fourth workpackage innovative solar cell prototypes were assembled and tested. In this sense, first solar cells reported ever with SbSeI and SbSeBr by physical vapor deposition techniques were obtained, with very promising efficiencies and open circuit voltages exceeding 600 mV, opening relevant perspectives for this new family of materials for energy applications.
In the second workpackage, a complete screeing of electron and hole selective contacts was performed, defining the most suited devices architectures for the new materials under development. Deep surface analysis and chemical modification was performed, in order to manage the surface properties for interfaces optimization. On the other hand, a new type of conjugated electrolytes with fractal geometry have been developed as dipolar molecules for enhancing contact selectivity, and demonstrated for the first time in an emerging thin film technology.
In the third workpackage, a new methodology for the synthesis of complex van der Waals chalco-halide compounds was developed, based on the coevaporation of a chalcogenide compound a followed by a high pressure annealing. A completely new family of compounds including SbSI, SbSeI, SbSBr, SbSeBr, BiSI, BiSeI, BiSBr and BiSeBr were synthesized, and their quasi-one-dimensional structure demonstrated. Fundamental properties of these new type of materials were investigated through a complete advanced characterization, and the different possible applications of each of them was analysied.
Finally, in the fourth workpackage innovative solar cell prototypes were assembled and tested. In this sense, first solar cells reported ever with SbSeI and SbSeBr by physical vapor deposition techniques were obtained, with very promising efficiencies and open circuit voltages exceeding 600 mV, opening relevant perspectives for this new family of materials for energy applications.
SENSATE is innovating in several aspects the current state of the art of van der Waals materials with quasi-one-dimensional structure. The project has introduced innovative ideas in the synthesis of these complex materials, demonstrating for the first time their synthesis by physical vapor deposition routes, thanks to the development of a customized high pressure reactive annealing. This allows also controlling the morphology and orientation of the quasi-one-dimensional columns naturally formed by the Sb and Bi chalco-halides. This accurate control of composition and morphology is opening very relevant perspectives for the application of these materials in several energy related technologic fields, such as solar cells and photocatalysis. In addition, new contacting layers with high selectivity are under development, demonstrating for the first time a selective contact for emerging thin film photovoltaic technologies using unconventional dipolar molecules with fractal properties.
The project has also progress beyond the state of the art of this technologies, by implementing simultaneously dive and materials modeling. In devices modeling, a complete new model for chalco-halide solar cells with different selective contacts were developed. In materials modeling, the combination of DFT calculations with machine learning concepts gives the possibility to simulate the properties of complex solid solution alloys in a wide range of composition, using standard computing resources. The predictions from this combined model were confirmed experimentally.
Finally, SENSATE also innovate in presenting the first solar cell prototypes with this van der Waals materials, and demonstrating encouraging conversion efficiencies and voltages well beyond the 600 mV, highlighting the potential of these materials for energy conversion. Starting from now, SENSATE will concentrate the efforts in consolidating the synthesis route of these compounds, analyzing the formation mechanisms, and establishing the routes for a complete morphology-electric-optic properties control. Based on the obtained results, improved solar cell devices architectures are planned, using unconventional contacts that can bring clear advantages to the peculiar quasi-one-dimensional columnar structure of these emerging chalco-halides. Other possible energy related applications are also under investigation, including the photocatalytic conversion of water to for clean hydrogen. Finally, due to the versatility of the developed methodology for the synthesis of chalco-halides, other compounds such as anti-perovskite materials will be synthesized and investigated. The application of one patent on this synthesis method is expected in the next months.
In overall, the project is innovating in many aspects from the demonstration of the synthesis of new materials, the theoretical modeling, new selective contacts, up to the assembly or disruptive devices, with novel van der Waals chalco-halide semiconductors.
The project has also progress beyond the state of the art of this technologies, by implementing simultaneously dive and materials modeling. In devices modeling, a complete new model for chalco-halide solar cells with different selective contacts were developed. In materials modeling, the combination of DFT calculations with machine learning concepts gives the possibility to simulate the properties of complex solid solution alloys in a wide range of composition, using standard computing resources. The predictions from this combined model were confirmed experimentally.
Finally, SENSATE also innovate in presenting the first solar cell prototypes with this van der Waals materials, and demonstrating encouraging conversion efficiencies and voltages well beyond the 600 mV, highlighting the potential of these materials for energy conversion. Starting from now, SENSATE will concentrate the efforts in consolidating the synthesis route of these compounds, analyzing the formation mechanisms, and establishing the routes for a complete morphology-electric-optic properties control. Based on the obtained results, improved solar cell devices architectures are planned, using unconventional contacts that can bring clear advantages to the peculiar quasi-one-dimensional columnar structure of these emerging chalco-halides. Other possible energy related applications are also under investigation, including the photocatalytic conversion of water to for clean hydrogen. Finally, due to the versatility of the developed methodology for the synthesis of chalco-halides, other compounds such as anti-perovskite materials will be synthesized and investigated. The application of one patent on this synthesis method is expected in the next months.
In overall, the project is innovating in many aspects from the demonstration of the synthesis of new materials, the theoretical modeling, new selective contacts, up to the assembly or disruptive devices, with novel van der Waals chalco-halide semiconductors.