Scientists in the U.S. demonstrated an additive that acts as a “molecular glue” within a perovskite solar cell. Treating the cells with this self-assembled monolayer material was shown to greatly improve their long-term performance, whilst also providing a boost to conversion efficiency. And the scientists further point out that the treatment relies on simple processing and readily available materials – good signs for its applicability in manufacturing.
Scientists in China took a closer look at the role of defects in limiting the performance of perovskite solar cells, demonstrating a screening effect that could be tuned to make material defects “invisible” to charge carriers, greatly improving cell performance. Using this approach they demonstrate a 22% efficient inverted perovskite solar cell, and theorize several new pathways to even higher performance.
Scientists have set a new efficiency record for a single-junction perovskite solar cell at 25.6%. The cell additionally showed operational stability for 450 hours, and intense electroluminescence with external quantum efficiencies of more than 10%.
Chinese scientists have powered two electrochromic devices with a perovskite solar cell based on a hole transporting material made of poly(triarylamine) (PTAA). The cell has an open-circuit voltage of 1.02 V, a short-circuit current of 22.8 mA/cm2, and a fill factor of 78.4%. When solar radiation is higher, the cells drive the electrochromic devices into a dark state, which in turn reduces the light that can enter a building.
Taiwanese researchers have added bathocuproine (BCP) molecules to three different kinds of solvents used in perovskite cells and have ascertained how this combination increases the carrier mobility and passivates the electron-poor defects. Furthermore, they utilized a polyelectrolyte (P3CT-Na) thin film as hole transporting material instead of commonly-used thin films based on PEDOT:PSS.
An international research team has developed a PV cell with all-inorganic cesium-lead iodide (CsPbI3) perovskite. The scientists added phenyl-C61-butyric acid methyl ester (PCBM), one of the best electron acceptors in organic PV cells, into the CsPbI3 quantum dot layer.
Scientists in Singapore have conducted a review of all existing methods to produce colorful opaque and semitransparent perovskite solar cells for applications in BIPV and urban environments. They identified two general approaches consisting of coloring the perovskites via external or internal modifications.
A Russian-Italian research group has developed a two-dimensional transition metal carbide, known as MXenes, to collect photocurrent in perovskite cells. The cells were built with an inverted configuration and are based on a nickel(II) oxide hole transporting layer. The scientists claim that the doping technique allowed them to increase the efficiency of the cell by more than 2%.
International researchers have developed a silicon heterojunction PV cell with textured surfaces to accommodate the perovskite top cell. They optimized the rear transparent electrode to collect as much albedo as possible and achieved five different perovskite bandgaps by altering the iodide-to-bromide ratio in the perovskites, resulting in a higher open-circuit voltage.
Italian researchers have engineered a hole extraction layer with water-splitting additives to reduce the impact of moisture in perovskite PV devices. They claim that the method ensured a power conversion efficiency of more than 9% in perovskite cells stored for a month in a water-saturated atmosphere.