Fundamentals of Energy Conversion Processes
A DFG Cluster of Excellence
News
Supercapacitors challenge batteries
2021-01-15T18:26:47+01:00Jan 11, 2021|
Supercapacitors store and release energy very fast but have a low energy density. This might change due to a powerful graphene hybrid material developed by the team of Roland Fischer.
Layers step out of line
2021-01-15T18:29:13+01:00Dec 17, 2020|
If the stacking structure of the “miracle material” COF is slightly shifted, its properties change dramatically. This happens more often than assumed, as chemists from e-conversion could demonstrate.
Events

e-conversion conference 2021
Unfortunately we had to cancel our conference planned for September 2020. All the more we are looking forward to welcome our guests in Venice in September 2021!
Recent Publications
E Cortés, L V Besteiro, A Alabastri, A Baldi, G Tagliabue, A Demetriadou, P Narang Challenges in Plasmonic Catalysis Journal Article In: ACS Nano, 14 (12), pp. 16202-16219, 2020, ISSN: 1936-0851. @article{, title = {Challenges in Plasmonic Catalysis}, author = {E Cort\'{e}s and L V Besteiro and A Alabastri and A Baldi and G Tagliabue and A Demetriadou and P Narang}, url = {https://doi.org/10.1021/acsnano.0c08773}, doi = {10.1021/acsnano.0c08773}, issn = {1936-0851}, year = {2020}, date = {2020-12-22}, journal = {ACS Nano}, volume = {14}, number = {12}, pages = {16202-16219}, abstract = {The use of nanoplasmonics to control light and heat close to the thermodynamic limit enables exciting opportunities in the field of plasmonic catalysis. The decay of plasmonic excitations creates highly nonequilibrium distributions of hot carriers that can initiate or catalyze reactions through both thermal and nonthermal pathways. In this Perspective, we present the current understanding in the field of plasmonic catalysis, capturing vibrant debates in the literature, and discuss future avenues of exploration to overcome critical bottlenecks. Our Perspective spans first-principles theory and computation of correlated and far-from-equilibrium light\textendashmatter interactions, synthesis of new nanoplasmonic hybrids, and new steady-state and ultrafast spectroscopic probes of interactions in plasmonic catalysis, recognizing the key contributions of each discipline in realizing the promise of plasmonic catalysis. We conclude with our vision for fundamental and technological advances in the field of plasmon-driven chemical reactions in the coming years.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The use of nanoplasmonics to control light and heat close to the thermodynamic limit enables exciting opportunities in the field of plasmonic catalysis. The decay of plasmonic excitations creates highly nonequilibrium distributions of hot carriers that can initiate or catalyze reactions through both thermal and nonthermal pathways. In this Perspective, we present the current understanding in the field of plasmonic catalysis, capturing vibrant debates in the literature, and discuss future avenues of exploration to overcome critical bottlenecks. Our Perspective spans first-principles theory and computation of correlated and far-from-equilibrium light–matter interactions, synthesis of new nanoplasmonic hybrids, and new steady-state and ultrafast spectroscopic probes of interactions in plasmonic catalysis, recognizing the key contributions of each discipline in realizing the promise of plasmonic catalysis. We conclude with our vision for fundamental and technological advances in the field of plasmon-driven chemical reactions in the coming years. |
J B Lee, H Walker, Y Li, T W Nam, A Rakovich, R Sapienza, Y S Jung, Y S Nam, S A Maier, E Cortés Template Dissolution Interfacial Patterning of Single Colloids for Nanoelectrochemistry and Nanosensing Journal Article In: ACS Nano, 2020, ISSN: 1936-0851. @article{, title = {Template Dissolution Interfacial Patterning of Single Colloids for Nanoelectrochemistry and Nanosensing}, author = {J B Lee and H Walker and Y Li and T W Nam and A Rakovich and R Sapienza and Y S Jung and Y S Nam and S A Maier and E Cort\'{e}s}, url = {https://doi.org/10.1021/acsnano.0c09319}, doi = {10.1021/acsnano.0c09319}, issn = {1936-0851}, year = {2020}, date = {2020-12-03}, journal = {ACS Nano}, abstract = {Deterministic positioning and assembly of colloidal nanoparticles (NPs) onto substrates is a core requirement and a promising alternative to top-down lithography to create functional nanostructures and nanodevices with intriguing optical, electrical, and catalytic features. Capillary-assisted particle assembly (CAPA) has emerged as an attractive technique to this end, as it allows controlled and selective assembly of a wide variety of NPs onto predefined topographical templates using capillary forces. One critical issue with CAPA, however, lies in its final printing step, where high printing yields are possible only with the use of an adhesive polymer film. To address this problem, we have developed a template dissolution interfacial patterning (TDIP) technique to assemble and print single colloidal AuNP arrays onto various dielectric and conductive substrates in the absence of any adhesion layer, with printing yields higher than 98%. The TDIP approach grants direct access to the interface between the AuNP and the target surface, enabling the use of colloidal AuNPs as building blocks for practical applications. The versatile applicability of TDIP is demonstrated by the creation of direct electrical junctions for electro- and photoelectrochemistry and nanoparticle-on-mirror geometries for single-particle molecular sensing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Deterministic positioning and assembly of colloidal nanoparticles (NPs) onto substrates is a core requirement and a promising alternative to top-down lithography to create functional nanostructures and nanodevices with intriguing optical, electrical, and catalytic features. Capillary-assisted particle assembly (CAPA) has emerged as an attractive technique to this end, as it allows controlled and selective assembly of a wide variety of NPs onto predefined topographical templates using capillary forces. One critical issue with CAPA, however, lies in its final printing step, where high printing yields are possible only with the use of an adhesive polymer film. To address this problem, we have developed a template dissolution interfacial patterning (TDIP) technique to assemble and print single colloidal AuNP arrays onto various dielectric and conductive substrates in the absence of any adhesion layer, with printing yields higher than 98%. The TDIP approach grants direct access to the interface between the AuNP and the target surface, enabling the use of colloidal AuNPs as building blocks for practical applications. The versatile applicability of TDIP is demonstrated by the creation of direct electrical junctions for electro- and photoelectrochemistry and nanoparticle-on-mirror geometries for single-particle molecular sensing. |
M T Sirtl, M Armer, L K Reb, R Hooijer, P Dörflinger, M A Scheel, K Tvingstedt, P Rieder, N Glück, P Pandit, S V Roth, P Müller-Buschbaum, V Dyakonov, T Bein Optoelectronic Properties of Cs2AgBiBr6 Thin Films: The Influence of Precursor Stoichiometry Journal Article In: ACS Applied Energy Materials, 2020. @article{, title = {Optoelectronic Properties of Cs2AgBiBr6 Thin Films: The Influence of Precursor Stoichiometry}, author = {M T Sirtl and M Armer and L K Reb and R Hooijer and P D\"{o}rflinger and M A Scheel and K Tvingstedt and P Rieder and N Gl\"{u}ck and P Pandit and S V Roth and P M\"{u}ller-Buschbaum and V Dyakonov and T Bein}, url = {https://doi.org/10.1021/acsaem.0c01308}, doi = {10.1021/acsaem.0c01308}, year = {2020}, date = {2020-11-25}, journal = {ACS Applied Energy Materials}, abstract = {Lead-free double perovskites have recently attracted growing attention as possible alternatives to lead-based halide perovskites in photovoltaics and other optoelectronic applications. The most prominent compound Cs2AgBiBr6, however, presents issues such as a rather large and indirect band gap, high exciton binding energies, and poor charge carrier transport, especially in thin films. In order to address some of these challenges, we systematically modified the stoichiometry of the precursors used for the synthesis of thin films toward a BiBr3-deficient system. In combination with a stoichiometric excess of AgBr, we obtained highly oriented double perovskite thin films. These modifications directly boost the lifetime of the charge carriers up to 500 ns as observed by time-resolved photoluminescence spectroscopy. Moreover, time-resolved microwave conductivity studies revealed an increase of the charge carrier mobility from 3.5 to around ∼5 cm2/(V s). Solar cells comprising the modified films as planar active layers reached power conversion efficiency (PCE) values up to 1.11%, exceeding the stoichiometric reference film (∼0.97%), both on average and with champion cells. The results in this work underline the importance of controlling the nanomorphology of the bulk film. We anticipate that control of precursor stoichiometry will also offer a promising approach for enhancing the efficiency of other perovskite photovoltaic absorber materials and thin films.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Lead-free double perovskites have recently attracted growing attention as possible alternatives to lead-based halide perovskites in photovoltaics and other optoelectronic applications. The most prominent compound Cs2AgBiBr6, however, presents issues such as a rather large and indirect band gap, high exciton binding energies, and poor charge carrier transport, especially in thin films. In order to address some of these challenges, we systematically modified the stoichiometry of the precursors used for the synthesis of thin films toward a BiBr3-deficient system. In combination with a stoichiometric excess of AgBr, we obtained highly oriented double perovskite thin films. These modifications directly boost the lifetime of the charge carriers up to 500 ns as observed by time-resolved photoluminescence spectroscopy. Moreover, time-resolved microwave conductivity studies revealed an increase of the charge carrier mobility from 3.5 to around ∼5 cm2/(V s). Solar cells comprising the modified films as planar active layers reached power conversion efficiency (PCE) values up to 1.11%, exceeding the stoichiometric reference film (∼0.97%), both on average and with champion cells. The results in this work underline the importance of controlling the nanomorphology of the bulk film. We anticipate that control of precursor stoichiometry will also offer a promising approach for enhancing the efficiency of other perovskite photovoltaic absorber materials and thin films. |