Researchers from Solliance partners Delft University of Technology, Eindhoven University of Technology and TNO have developed a tandem perovskite-silicon solar cell using a new approach to interface engineering. 

The team's findings demonstrate the potential of using (n)nc-SiOx:H and (n)nc-Si:H interfacial layers in tandem solar cells to minimize reflection losses at the interfaces between the perovskite and silicon sub-cells, as explained by the scientists. Through optimizing interference effects, these light management techniques can be applied to various tandem structures.

American Perovskites (AP), a material and equipment supply company, has recently been named a finalist in the American-Made Startup Contest and awarded $200,000 to synthesize a novel family of polymer hole transport materials. AP is working with a host of players including Colorado School of Mines, TDA Research, TandemPV, and The University of Toledo. Their innovation is industrial synthesis of a novel family of polymer hole transport materials with excellent reliability, optical properties, and cost.

Another finalist in this contest was Perotech Energy, whose innovation is developing perovskite bifacial modules using high throughput and low-cost solution process with high stability and energy yield. 

Researchers fromKorea's Pohang University of Science and Technology (POSTECH), Ajou University, Daegu Gyeongbuk Institute of Science and Technology (DGIST) and Kookmin University have designed new polymeric hole transport materials that constitute a crucial element in perovskite quantum dot solar cells, leading to significant increase in their efficiency. 

The team's hole transport materials include polymers based on sulfur and selenium compounds. These polymers exhibit structural features, such as planarization and locking of intermolecular arrangements, which increase charge mobility. Furthermore, asymmetric alkyl substituents of the polymers facilitate molecular interactions, thereby complementing the electrical properties of cells.

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.

Hanwha Q Cells, the solar panel unit of Hanwha Solutions Corp., has announced a large investment of 136.5 billion won (around USD$102 million) to establish a test facility for mass production of perovskite-silicon tandem cells and modules at its Jincheon plant in North Chungcheong Province. The trial operations for the new facility are scheduled to begin in the latter half of next year.

In collaboration with its German R&D center in Talheim, which currently operates a small-scale test production line for R&D purposes, the company plans to launch full-scale mass production of tandem cells in the second half of 2026.

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.

Researchers from the National University of Singapore (NUS), led by Professor Liu Xiaogang from the Department of Chemistry, have developed a perovskite-based 3D imaging sensor that has an extremely high angular resolution, which is the capacity of an optical instrument to distinguish points of an object separated by a small angular distance, of 0.0018o. This innovative sensor operates on a unique angle-to-colour conversion principle, allowing it to detect 3D light fields across the X-ray to visible light spectrum.  

 Design of the 3D light-field sensor on the basis of pixelated color conversion. Image from study 

A light field encompasses the combined intensity and direction of light rays, which the human eyes can process to precisely detect the spatial relationship between objects. Traditional light sensing technologies, however, are less effective. Most cameras, for instance, can only produce two-dimensional images, which is adequate for regular photography but insufficient for more advanced applications, including virtual reality, self-driving cars, and biological imaging. These applications require precise 3D scene construction of a particular space.

Researchers from Russia's Alferov University, ITMO University, Far Eastern Branch of Russian Academy of Sciences, Peter the Great St. Petersburg Polytechnic University, Skolkovo Institute of Science and Technology and China's Qingdao Innovation and Development Center have developed a novel design for a perovskite electrochemical cell for light-emission and light-detection, where the active layer consists of a composite material made of halide perovskite microcrystals, polymer support matrix, and added mobile ions.

Schematic diagrams of (a) the typical PeLED device structure, where CTL - charge transfer layer, QD - quantum dots and (b) the team's PeLEC device structure, where SWCNT - single-walled carbon nanotubes. Image from Opto-Electronic Advances.

The team explained that while halide perovskite light-emitting devices exhibit exceptional properties such as high efficiency, high color purity, and broad color gamut, their industrial integration generally suffers from the technological complexity of devices' multilayer structure alongside in-operation induced heating poor stability. Halide perovskite light-emitting electrochemical cells are a novel type of perovskite optoelectronic device that differs from the perovskite light-emitting diodes by a simple monolayered architecture. 

Japan-based chemicals company, Kaneka, has reported the design of a two-terminal (2T) perovskite-crystalline tandem solar cell using a 145 μm thick industrial Czochralski (CZ) silicon wafer. The cell has an anti-reflection intermediate layer relying on what Kaneka calls “gentle textured structures” that were applied on the front side of the bottom, which reportedly enables a significant improvement in the typical light confinement effects in perovskite-silicon tandem devices.

“Light management technology is mandatory to fully utilize the wide range of the solar spectrum in a solar cell, especially for a 2T tandem structure, since its top and bottom cells are electrically connected in series and required to satisfy the constraints of current matching whereby the respective currents at the operating point are aligned to some extent,” the scientists said in their work. “Because of the large difference in the refractive indices between perovskite and crystalline silicon (c-Si) materials, the optimized intermediate layer as shown acts as an anti-reflection coating to suppress the reflection loss of the infrared light that is utilized in the bottom cell.”