research
Halide Perovskite Materials
In the last 10 years, metal halide perovskites emerged for their superior optoelectronic properties, making great strides in photovoltaic (PV) and light emitting applications. Some of the greatest advantages of MHPs are the use of earth-abundant materials, facile solution inexpensive processability, defect tolerance and, above all, the tunability of their energy bandgap (Eg) that can span from 1.2 to 2.3 eV simply changing the chemical composition, making them ideal candidates for a wide variety of applications, including indoor PV, multijunction tandem devices and solar battery chargers.
Water Pollution
Water pollution is the release of substances into the water that makes it unsafe for human use and disrupts aquatic ecosystems. Among these contaminants, organic compounds, e.g., dyes, pharmaceuticals, pesticides, which mainly come from anthropogenic sources, represent a serious concern because they cannot be efficiently eliminated in conventional wastewater treatment plants and they end up being released into natural water systems, where they can persist for long time, causing serious health problems like cancers and hormonal disruptions.
Solar-Driven Ectrochemical Oxidation Processes
Among the novel technologies developed to remove persistent organic pollutants from wastewater, electrochemical oxidation processes are found to be the most efficient, where a constant electrical current or potential is applied to an electrode immersed in the contaminated water for the in-situ generation of oxidizing agents (•OH radicals) that can efficiently degrade OP into less complex and less harmful compounds. Despite its efficiency in removing toxic organics at low concentrations, the high energy consumption under operation limit the widespread of this technology. Alternatively, free solar energy can be used to drive the electrochemical process, eliminating the high energy consumption impact and considerably reducing the costs of the whole technology.
Overview of BOLLA
BOLLA will design stable narrow bandgap (Nb, ~1.3 eV) and wide bandgap (Wb, ~1.9 eV) metal halide perovskite structures and engineer inexpensive printable solar cells that will be coupled with an electrochemical system to provide the necessary energy for the degradation of the most common organic pollutants found in water. The fundamental chemistry of defects and the related optoelectronic mechanisms will be investigated as primary source of material instability. Accordingly, the material processing of metal halide perovskites will be designed to avoid the presence of deep trap states and ensure chemical stability under operation. In order to assure reduced fabrication costs, organic-conductor-free devices that avoid the use of poorly stable and synthetically expensive conductive polymers will be engineered. These organic conductors will be entirely replaced by stable metal oxides (MOs) and inexpensive inorganic carbon compounds and the PV cells will be manufactured using methods compatible with large-scale production, such as spray coating, screen printing and dip coating, to advance the commercialization of the technology as inexpensive point-of-use water purification system.