Unmodified perovskite inks designed for conventional solution processing based on spin coating typically produce pinholed, uneven, and shunted films when processed in air or with scalable processing methods. Novel polymeric modifiers have recently been used to improve film uniformity and density. These additives act as rheological modifiers by increasing ink viscosity, thus allowing longer periods for crystallization and smooth films. The long chains of the polymer also create an organizational scaffold that increases resistance to humidity. In recent years, additives from the food industry, such as corn starch, have been found to enhance mechanical integrity and the operational lifetime of devices. These additives also have been found to induce spherulitic domains that can be tuned in size by temperature and precursor concentration to increase performance.
Researchers at Arizona State University have developed a novel method for scalable open-air flame processing of in-line thin film photovoltaic manufacturing using a gum-based polymer additive in a semiconducting halide perovskite ink. The additive is made from nontoxic starch and gum-based materials from the food industry, which improves the printability and processability of the ink to be compatible with rapid high-temperature processing. The use of a nontoxic solvent system further extends the wetting period, thus improving crystallization control. This invention also incorporates a high-temperature flame discharge to rapidly crystallize the perovskite, and the use of the additive enables the ability to adapt these rapid process conditions.
Solar cell manufacturing for applications in:
- UAVs and drones
- Residential & commercial solar installation
Benefits and Advantages
- High deposition rate (forms perovskite in less than 1/100 of time for typical solution-process material)
- Open-air environment
- Low-cost raw materials (more than 10x cheaper than conventional, silicon-based solar technology)
- High conversion yield (raw materials usage is 50x lower compared to spin-coated method)
- Scalable (amenable to high volume manufacturing)
- Increased mechanical properties (10x higher fracture energy compared to typical solution processed material)
- Increased reliability (tunable and compressive film stress)
Related Publication: Rapid Open-Air Fabrication of Perovskite Solar Modules.