SnCl2(acac)2 (from Merck KGaA, Darmstadt, Germany) is synthesized according to the procedure described in [36 (link),37 (link),38 (link)]. SnCl2 is mixed with acetylacetone and HCl. One wt% Triton X-100 (from Merck KGaA, Darmstadt, Germany) is added to the final solution in order to improve the wettability when spin coating on the quartz substrates. The solution is filtered with a 1 µm filter and spin coated at 2500 rpm, resulting in thin films with a thickness of approximately 900 nm ± 70 nm.
A commercially available Pd metal precursor solution (i.e., Pd(acac)2) is purchased from Merck KGaA, Darmstadt, Germany and 0.5 wt% of Pd(acac)2 is added to the SnCl2(acac)2 solution applied for spin coating.
A commercially available Pd metal precursor solution (i.e., Pd(acac)2) is purchased from Merck KGaA, Darmstadt, Germany and 0.5 wt% of Pd(acac)2 is added to the SnCl2(acac)2 solution applied for spin coating.