Efficiency - Page 2

Researchers from Japan's Chiba University, Kyoto University and the University of Electro-Communications have developed a universal, physics-based model that clarifies how energy levels align at electrode/hole-collecting-monolayer (HCM)/perovskite interfaces in inverted perovskite solar cells and how this alignment controls hole extraction and device performance. 

The new work replaces competing interface models - such as vacuum level alignment, Fermi level alignment, and electrode-modified Schottky models - with a single framework that treats the stack as two coupled but distinct interfaces. At the electrode/HCM contact, the alignment is governed by an interface dipole at a metal/organic interface, where the HCM acts as a dipole layer that shifts the electrode work function. At the HCM/perovskite boundary, both layers are treated as semiconductors and described using semiconductor heterojunction theory, with band offsets and band bending rather than simple vacuum-level matching.

Nanchang University researchers recently reported a molecular doping strategy that addresses a central bottleneck in formamidinium–cesium (FA_1−xCs_xPbI₃) perovskites: stabilizing the photoactive α-phase while maintaining high device efficiency and long-term operational stability.

Metal halide perovskites' large-scale deployment has been limited by phase instability and performance degradation. In FA–Cs systems, achieving the desired α-phase is particularly challenging because of limited incorporation of Cs⁺ ions and an incomplete understanding of the phase transition pathway. While two-step fabrication offers improved control over crystallization compared to one-step processing, it still struggles to deliver uniform cation distribution and stable phase formation. To address this, the team introduced a tailored additive, cesium 4-(diphenylphosphino)benzoate, designed to regulate Cs⁺ incorporation during film formation. 

Researchers from Korea University, Seoul National University, University of New South Wales, University of Toledo, Chonnam National University, Ulsan National Institute of Science and Technology, Cardiff University and the University of Surrey have reported a new strategy to enhance both the efficiency and stability of perovskite solar cells by leveraging a previously unrecognized interfacial phenomenon termed contact-triggered cationic interaction (CCI).

A schematic of CCI between framework-embedded molecules of 3D and 2D perovskites. Image from: Nature Energy

Unlike conventional approaches based on additive incorporation or surface passivation, CCI arises from simple physical contact between separately crystallized two-dimensional (2D) and three-dimensional (3D) perovskite films, without chemical bonding, intermixing or junction formation. At the interface, bulky spacer cations in the 2D perovskite deform and interact with formamidinium (FA) cations in the 3D lattice via dipole-induced dipole interactions. These interactions constrain the rotational freedom of the FA cations, effectively reducing molecular disorder. The strength of this interaction increases with alkyl chain length in the 2D layer, which provides more contact points and further restricts cation motion. As a result, CCI suppresses phase transitions, extends carrier lifetimes, and modifies photophysical behavior in a reversible manner.

Perovskite manufacturer Huarou PV has reported a power conversion efficiency of 31.73% achieved on its all-perovskite tandem solar cell, which has been certified by the National Photovoltaic Industry Measurement and Test Center (NPVM).

The cell demonstrated an open-circuit voltage of 2.224 V. This follows the company’s earlier announcement of 27.98% efficiency for a single-junction perovskite cell under standard illumination.

Researchers from Xi’an Jiaotong University and Shaanxi Puguang Weishi have tackled the issue of iodine (I₂) impurities that impair the photoelectronic properties of perovskite solar cells (PSCs).

Such impurities originate from the oxidation of iodide ions found in precursor solutions and perovskite films, and so the team systematically evaluated the effectiveness of two amide-based reducing agents, L-prolinamide (LPM) and 2,3-pyrazinedicarboxamide (LLM), as additives for mitigating detrimental I₂ impurities within perovskite.  

Researchers from the University of Tokyo have developed an all-perovskite double-junction solar cell approach that pushes efficiency to 30.2% in a spectral-splitting four-terminal configuration.

All-perovskite multijunction solar cells are a promising path toward higher photovoltaic efficiency, but the top cell must perform exceptionally well to unlock the full potential of the device. In this work, the team paired a highly efficient FAPbI₃ wide-bandgap top cell with an Sn-Pb mixed perovskite narrow-bandgap bottom cell, creating a mechanically flexible, independently optimized pair of subcells. By using a spectral splitter with a 775 nm cutoff wavelength, they achieved a champion power conversion efficiency of 30.2%, the highest reported for all-perovskite four-terminal spectral-splitting solar cells.

Researchers from the University of Rome Tor Vergata, Hellenic Mediterranean University, Université Grenoble Alpes (CNRS), Halocell Europe, CHOSE, ENEA, 3SUN - Enel Green Power and BeDimensional have developed a scalable four-terminal (4T) perovskite/silicon tandem architecture that combines high efficiency, semi-transparency and real-world stability by engineering a field effect junction directly inside the perovskite absorber. 

a Layout of the semi-transparent 2D material-based PSMs. Each module is composed by 24 series-connected solar cells with an active area of 2.49 cm². The total active area is 60 cm² while the aperture area (comprising the interconnection areas) is about 63 cm². b Demonstrator 1 (DEM1) perovskite/Si tandem panel. Each building block is composed of four parallel-connected semi-transparent perovskite modules stacked above the M2 Si-HJT bifacial cell (provided by 3SUN). c, d Pictures of the front and back side of the laminated tandem DEM1. Image from: Nature Communications

The work targets industrially relevant, large-area modules compatible with standard silicon wafer dimensions and production lines, addressing key bottlenecks in the commercialization of perovskite/Si tandems such as scalability, efficiency loss on upscaling, and outdoor durability.

A research team, led by the Chinese Academy of Sciences (CAS), has developed a novel chemical polishing approach to improve the performance of perovskite/silicon tandem solar cells (PVSK/Si TSCs), achieving a power conversion efficiency (PCE) increase from 30.04% to 31.83%.

In conventional tandem devices fabricated using spin-coating techniques, the bottom crystalline silicon layer typically features sub-micron pyramid (SMP) textures. These pyramid structures, though essential for light trapping, produce deep V-shaped grooves between adjacent pyramids, which hinder substrate wettability and raise surface roughness. Such morphologies make it difficult to deposit uniform, defect-free perovskite films, ultimately limiting device efficiency. To address these issues, the team applied an isotropic etching-based chemical polishing process to smooth the V-shaped regions of the SMP texture. 

Researchers from Bar-Ilan University, Israel; the Institute of Astronomy Space and Earth Science, India; Prabhat Kumar College, India; the University of Waterloo, Canada; the University of Goettingen, Germany; Sidho-Kanho-Birsha University, India; and the Indian Institute of Science, India have developed mini perovskite solar modules that combine competitive efficiency with over 1,300 hours of operational stability by engineering the buried hole-transport interface with reduced graphene oxide (r-GO). 

The work targets one of the main bottlenecks in perovskite photovoltaics - scaling from high-efficiency small cells to stable, larger-area modules - by systematically passivating the interface between a self-assembled monolayer (SAM)-based hole transport layer (HTL) and the perovskite absorber.

Researchers from Wuhan University, Foshan Xianhu Laboratory, Wuhan University of Technology and UtmoLight have developed a processing-enabled strategy that continuously tunes the electronic properties of indium tin oxide (ITO) for improving the performance and thermal stability of inverted perovskite solar cells (PSCs). 

The method leverages oxygen-flux-controlled reactive plasma deposition (RPD) to finely adjust the carrier concentration, work function, and band-edge alignment of ITO thin films - without altering the device architecture.