TY - GEN A1 - Morales, Carlos A1 - Plate, Paul A1 - Marth, Ludwig A1 - Naumann, Franziska A1 - Kot, Małgorzata A1 - Janowitz, Christoph A1 - Kus, Peter A1 - Zöllner, Marvin Hartwig A1 - Wenger, Christian A1 - Henkel, Karsten A1 - Flege, Jan Ingo T1 - Bottom-up design of a supercycle recipe for atomic layer deposition of tunable Indium Gallium Zinc Oxide thin films T2 - ACS Applied Electronic Materials N2 - We present a successful bottom-up approach to design a generic plasma-enhanced atomic layer deposition (PEALD) supercycle recipe to grow high-quality indium gallium zinc oxide (IGZO) thin films with tunable composition at a relatively low temperature of 150 °C. In situ real-time ellipsometric characterization in combination with ex situ complementary techniques has been used to optimize the deposition process and quality of the films by identifying and solving growth challenges such as degree of oxidation, nucleation delays, or elemental composition. The developed supercycle approach enables facile control of the target composition by adapting the subcycle ratios within the supercycle process. Compared to other low-temperature deposition techniques resulting in amorphous films, our PEALD–IGZO process at 150 °C results in nearly amorphous, nanocrystalline films. The preparation of IGZO films at low temperature by a supercycle PEALD approach allows controlling the thickness, composition, and electrical properties while preventing thermally induced segregation. KW - IGZO KW - PEALD KW - supercycle KW - XPS depth profiling KW - current density Y1 - 2024 U6 - https://doi.org/10.1021/acsaelm.4c00730 SN - 2637-6113 VL - 6 IS - 8 SP - 5694 EP - 5704 PB - American Chemical Society (ACS) ER - TY - GEN A1 - Gawlińska-Nęcek, Katarzyna A1 - Kot, Małgorzata A1 - Starowicz, Zbigniew A1 - Janusz-Skuza, Marta A1 - Panek, Piotr A1 - Marth, Ludwig A1 - Plate, Paul A1 - Flege, Jan Ingo T1 - Reaction dynamics between formamidinium lead iodide and Copper Oxide T2 - ACS Applied Materials & Interfaces N2 - Copper oxide (CuOx) has been announced as a very promising hole-transporting layer for perovskite solar cells. However, in our previous work, we have shown that once a formamidinium lead triiodide (FAPI) perovskite is spin-coated on a spray-coated cuprous oxide (Cu2O) substrate, the Cu2O diffuses into and reacts with the FAPI film. In order to verify if the degradation products are related to the oxidation state of CuOx and/or its preparation method, in this work, we first prepared CuOx films by thermal oxidation at temperatures ranging from 120 to 300 °C. While increasing the process temperature, a transformation from copper I (Cu2O) to copper II (CuO) oxidation states was observed. For both oxidation states of copper, FAPI perovskite degradation was found; however, some alterations in the reaction products were noticed. In contrast to our expectations, the introduction of an ultrathin plasma-enhanced atomic layer deposited Al2O3 layer in between both films only partially blocked the CuOx migration into the FAPI film. It can be concluded that regardless of the chemical composition and/or preparation method of CuOx, the overlayered FAPI film gets decomposed. In order to use CuOx as a hole-transporting layer in solar cells, new strategies must be developed to limit these unwanted chemical reactions. KW - copper oxide hole-transporting layer KW - formamidinium lead iodide instability KW - perovskite solar cells KW - atomic layer deposition KW - aluminum oxide Y1 - 2024 U6 - https://doi.org/10.1021/acsami.4c12990 SN - 1944-8244 VL - 16 IS - 42 SP - 57878 EP - 57887 PB - American Chemical Society (ACS) ER - TY - GEN A1 - Kot, Małgorzata A1 - Kedia, Mayank A1 - Plate, Paul A1 - Marth, Ludwig A1 - Henkel, Karsten A1 - Flege, Jan Ingo T1 - Application of plasma enhanced atomic layer deposition process of alumina on perovskite film boosts efficiency of solar cells T2 - Verhandlungen der DPG N2 - It is assumed that plasma-enhanced atomic layer deposition (PEALD) cannot be used to prepare thin films on sensitive organic-inorganic perovskites because the plasma destroys the perovskite film and thus deteriorates its photophysical properties. Here, we prove that using an appropriate geometry of the ALD system (SENTECH SI PEALD system) and suitable process parameters it is possible to coat perovskites with alumina by PEALD. Spectromicroscopy followed by electrical characterisation reveal that as long as the PEALD process is not optimized (too long plasma pulses) one gets degradation of the perovskite as well as dissociation of the created iodine pentoxide (during PEALD) under light that causes a valence band maximum (VBM) shift to the Fermi level and thus significantly decreases the solar cell efficiency. However, once the PEALD process parameters are optimized, no VBM shift is observed. Moreover, the solar cell efficiency depends inversely on process temperature and layer thickness. KW - Plamsa-enhanced atomic layer deposition KW - Perovskite solar cells KW - Valence band maximum Y1 - 2023 UR - https://www.dpg-verhandlungen.de/year/2023/conference/skm/part/hl/session/4/contribution/2 SN - 0420-0195 PB - Deutsche Physikalische Gesellschaft CY - Bad Honnef ER -