Engineers at Rice University have created what they call microscopic seeds for growing incredibly uniform two-dimensional perovskite crystals that are stable and highly energy-efficient at harvesting electricity from sunlight. Perovskites are a class of materials that are extremely useful in building solar panels and are being investigated as a potential replacement for conventional solar panel materials. Halide perovskites are an organic material made from abundant and inexpensive ingredients.
Engineers from Rice University used a seeded growth method that addresses both the performance and production issues holding back halide perovskite photovoltaic technology in the past. Engineers from the Rice Brown School of Engineering published a study recently describing how to make the seeds and use them to grow homogeneous thin films. This type of thin-film is a highly sought after material that is comprised of uniformly thick layers.
Laboratory tests proved that photovoltaic devices made from thin films are both efficient and reliable, something that previous devices made from either 3D or 2D perovskites lacked. Study co-author Aditya Mohite says the team came up with a method where they can tailor the properties of the macroscopic films by first tailoring what they put into the solution. Mohite said you could arrive at something very homogeneous in size and properties, leading to higher efficiency by controlling what is put into the solution.
Researchers were able to get almost state-of-the-art device efficiency for the 2D case of 17 percent without optimization, and the team believes they can improve on that in several ways. The homogeneous films are expected to lead to optoelectronic devices with high efficiency and technologically relevant stability. The scene-growth method developed at Rice produces high-efficiency photovoltaic films that are stable, preserving more than 97 percent of their peak efficiency after 800 hours under illumination without thermal management.