Paper by Pía Vasquez

Here you'll find Pia's paper
"The properties of inorganic thin films (20 nm) featuring indium-free junctions between bottom and top cell of two-terminal perovskite/silicon heterojunction tandem structures have been investigated, namely p-doped hydrogenated nanocrystalline silicon, molybdenum and tungsten oxide, and cuprous oxide. Systematic characterization of the optical, structural and electrical properties of these materials deposited on SHJ substrates, compared to those of glass- and crystalline silicon reference samples is carried out and the validity of fast, reference characterization versus more complex, complete solar cell stack characterization is assessed. Spin coating deposition of wide bandgap (Eg = 1.73 eV) perovskite formulation in all substrates was chemically characterized. Results indicate that deposition of all HTL materials do not impact SHJ substrate passivation, or its optical properties. At a chemical level, high surface energy of (p + )nc-Si:H and MoOx, WOx surfaces allow proper perovskite deposition without need of surface treatment, evidenced by X-Ray diffraction and photoluminiscence spectroscopy measurements. Energy bandgaps of perovskite were measured around the nominal value of 1.75 eV, and PbI2/ PK ratios lower than 0.2, with the expected cubic phase and preferred crystalline orientations in the [0 1 1] family of planes. Perovskite crystallization on Cu2O surface shows prevailing PbI2 phases with a blue-shifted Eg, therefore, the as-deposited thin film does not favor perovskite nucleation and needs further investigation."