Perovskite applications

Researchers from CNR-IMM,CNR-IPCB, CNR-NANOTEC, Università Degli Studi di Messina and the University of Basel have shown that lead leakage can be prevented by applying a transparent titanium dioxide (TiO₂) sponge in a semitransparent solar cell. The device has demonstrated comparable efficiency to semi-transparent perovskite devices and has an average visible transmittance (AVT) of 31.4%.

The team designed the solar cell for applications such as building-integrated photovoltaics (BIPV) and agrivoltaics, in which the potential lead leakage can be seen as a serious public environmental and health risk source. 

Researchers from Nanjing Tech University, Wuhan University of Technology and National University of Singapore set out to address two major issues that should be resolved in order to promote perovskite solar cells (PSCs): disorder crystallization of perovskite and unbalanced interface charge extraction, which limit further improvements in device efficiency. 

The team used a thermally polymerized additive N-vinyl-2-pyrrolidone (NVP) as a polymer template in the perovskite film, followed by a conventional HTL/Chlorobenzene (CB) solution spin-coating process to remove the residual miscellaneous phases and open the grain boundaries to form monolithic perovskite grains, thereby suppressing the defect-related non-radiative recombination. Furthermore, this process results in the formation of a novel “Mortise-Tenon” (M-T) structure for perovskite/HTL composite film, which provides a larger contact area between perovskite and HTL, thereby facilitating hole extraction to achieve balanced charge management. 

An international team of scientists from Fritz Haber Institute of the Max Planck Society, École Polytechnique in Paris, Columbia University in New York, and the Free University in Berlin have demonstrated laser-driven control of fundamental motions of the lead halide perovskite (LHP) atomic lattice.

Sketch of the experimental pump-probe configuration. Image from Science Advances

By applying a sudden electric field spike faster than a trillionth of a second (picosecond) in the form of a single light cycle of far-infrared Terahertz radiation, the team unveiled the ultrafast lattice response, which might contribute to a dynamic protection mechanism for electric charges. This precise control over the atomic twist motions could allow to create novel non-equilibrium material properties, potentially providing hints for designing the solar cell material of the future.

A Department of Energy (DoE) project, lead by University of Michigan's Prof. Zetian Mi, is using perovskites to develop high efficiency, low cost, and ultrastable production of green hydrogen fuels directly from sunlight and water.

The new method to achieve clean hydrogen through solar water splitting offers a promising path to achieving net-zero carbon emissions. The University of Michigan research team aims to stabilize perovskite-based solar cells to produce highly-efficient, low-cost, ultrastable green hydrogen fuel.

Canon has announced that it has developed perovskite quantum-dot inks for use in next-generation displays, with improved durability and potential for application in high-image-quality displays.

Quantum dots are semiconductor nanocrystals that measure only a few nanometers in diameter and can emit light with high brightness and high color purity. Displays with quantum-dot technology are attracting growing attention due to their wide color gamut that makes possible high visual expressiveness. Therefore, quantum dots for display is sought to achieve higher color purity and higher light utilization efficiency. In addition, though cadmium (Cd) has thus far been the preferred material for quantum dots, due to environmental concerns, there is a growing interest in Cd-free materials.

Researchers from the University of North Carolina at Chapel Hill, University of Toledo and Perotech Energy have found that bathocuproine, which is often used as an electron-transport material, can improve power-conversion efficiency and stability when added to the hole-transport layer. 

The chelation product of bathocuproine with lead ions is insoluble in the perovskite ink and also decreases the formation of amorphous regions by reducing the amount of trapped dimethyl sulfoxide solvent. Minimodules with an aperture area of 26.9 square centimeters had a certified efficiency of 21.8% and light-soaking stability exceeding 2000 hours. 

University of Cambridge researchers have used perovskites to develop a solar-powered technology that converts carbon dioxide and water into liquid fuels that can be added directly to a car’s engine as drop-in fuel.  

The researchers relied on photosynthesis to convert CO₂, water and sunlight into multicarbon fuels – ethanol and propanol – in a single step. These fuels have a high energy density and can be easily stored or transported.

Scientists from the Nanjing University of Aeronautics and Astronautics in China and University of Okara in Pakistan have simulated a solar cell based on an absorber using a CsSnI₃ perovskite material, which is an inorganic perovskite that has low exciton binding energy, a high absorbance coefficient, and an energy bandgap of 1.3 eV.

The researchers used the SCAPS-1D solar cell capacitance software, which is a simulation tool for thin-film solar cells developed by the University of Ghent in Belgium, to simulate several cell designs with different electron transport layers (ETLs) and hole transport layers (HTLs). Through a series of simulations, the team found that the best possible cell configuration was provided by a device based on a substrate made of fluorine-doped tin oxide (FTO), a titanium oxide (TiO₂) ETL, the CsSnI₃ absorber, an HTL based on nickel(II) oxide (NiOx), and back electrodes.

Researchers from China's Henan University and Chinese Academy of Sciences (CAS) have reported an extremely efficient carbon electrode perovskite solar cell that reportedly achieves a power conversion efficiency of 20.8% while providing enhanced stability.

Schematic diagram of the fabrication process of bilayer HTL carbon electrode perovskite solar cells. Image from the study published in Journal of Materials Research and Technology

Commonly used metal contact electrodes can promote the degradation of perovskite solar cells due to the diffusion of metal impurities across the interfaces. This issue could be theoretically overcome by replacing the metal contact with carbon electrodes, which are highly promising for commercialization due to their ambient pressure processability based on industrially established printing techniques. The problem is, however,  that perovskite solar cells based on carbon electrodes lead to performance losses at the point where the carbon electrode meets the perovskite layer.

Researchers from the University of North Carolina at Chapel Hill have reported bifacial minimodules with front efficiency comparable to opaque monofacial counterparts, while gaining additional energy from albedo light. Their new design strategy could help to improve the efficiency and stability of bifacial perovskite solar cells. 

The scientists added a hydrophobic additive to the hole transport layer to protect the perovskite films from moisture. They also integrated silica nanoparticles with proper size and spacing in perovskite films to recover the absorption loss induced by the absence of reflective metal electrodes. The small-area single-junction bifacial perovskite cells achieved a power-generation density of 26.4 mW cm⁻² under 1 sun illumination and an albedo of 0.2. The bifacial minimodules showed front efficiency of over 20% and bifaciality of 74.3% and thus a power-generation density of over 23 mW cm⁻² at an albedo of 0.2. The bifacial minimodule retained 97% of its initial efficiency after light soaking under 1 sun for over 6,000 hours at 60 ± 5 °C.