Harvesting and storing solar energy is one of the main focal points of the drive towards a renewable energy economy. While photovoltaic cells allow the conversion of sunlight into electric current, additional storage technologies are required to match temporally fluctuating supply and demand. Photoelectrochemical water-splitting combines both light harvesting and energy storage into one device capable of producing hydrogen, from which the stored energy can be reclaimed at any desired time. Atomic layer deposition (ALD) is a method of growing thin films of various materials with unrivalled thickness control and uniformity, even on substrates with a complex or porous morphology.
I use ALD to prepare functional layers (i.e. photoabsorbers, charge-selective layers and catalysts) for photoelectrochemical systems as well as novel photovoltaic devices. I then use solid state and electrochemical characterization methods to examine the working mechanisms of the devices and improve their efficiency.
Alexander G. Hufnagel, ORCID: 0000-0003-4088-937X
1. A. G. Hufnagel, K. Peters, A. Müller, C. Scheu, D. Fattakhova-Rohlfing, T. Bein, “Zinc Ferrite Photoanode Nanomorphologies with Favorable Kinetics for Water-Splitting”, Adv. Funct. Mater. 2016, 26, 4435–4443. DOI: 10.1002/adfm.201600461
2. T. Sick, A. G. Hufnagel, J. Kampmann, I. Kondofersky, M. Calik, J. M. Rotter, A. Evans, M. Döblinger, S. Herbert, K. Peters, D. Böhm, P. Knochel, D. D. Medina, D. Fattakhova-Rohlfing, T. Bein, “Oriented Films of Conjugated 2D Covalent Organic Frameworks as Photocathodes for Water Splitting”, J. Am. Chem. Soc. 2018, 140, 2085-2092. DOI: 10.1021/jacs.7b06081
3. A. G. Hufnagel, A.-K. Henß, R. Hoffmann, O. E. O. Zeman, S. Häringer, D. Fattakhova-Rohlfing, T. Bein, “Electron-Blocking and Oxygen Evolution Catalyst Layers by Plasma-Enhanced Atomic Layer Deposition of Nickel Oxide”, Adv. Mater. Interfaces 2018, accepted for publication.
4. A. Binek, I. Grill, N. Huber, K. Peters, A. G. Hufnagel, M. Handloser, P. Docampo, A. Hartschuh, T. Bein, “Control of Perovskite Crystal Growth by Methylammonium Lead Chloride Templating”, Chem. Asian J. 2016, 11, 1199–1204. DOI: 10.1002/asia.201501379
5. Y. Hu, E. M. Hutter, P. Rieder, I. Grill, J. Hanisch, M. F. Aygüler, A. G. Hufnagel, M. Handloser, E. Ahlswede, T. Bein, A. Hartschuh, K. Tvingstedt, V. Dyakonov, A. Baumann, T. J. Savenije, M. L. Petrus, P. Docampo, “Understanding the Role of Cesium and Rubidium Additives in Perovskite Solar Cells: Trap States, Charge Transport and Recombination”, Adv. Energy Mater. 2018, 1703057. DOI: 10.1002/aenm.201703057
6. M. F. Aygüler, A. G. Hufnagel, P. Rieder, M. Wussler, N. Giesbrecht, W. Jaegermann, T. Bein, V. Dyakonov, M. Petrus, A. Baumann, P. Docampo, “Influence of Fermi Level Alignment with Tin Oxide on the Hysteresis of Perovskite Solar Cells”, ACS Appl. Mater. Interfaces 2018, 10, 11414-11419. DOI: 10.1021/acsami.8b00990