Perovskite Solar

Eternal Sun, developer of solar simulators for photovoltaic testing, has announced that Bolster Investment Partners has acquired an 80% majority stake in the company. 

The strategic partnership is set to accelerate Eternal Sun’s international expansion, product development, and professionalization. This milestone follows sustained growth and innovation in solar testing technology, including next-gen tandem and perovskite applications. Bolster brings not just capital, but also strategic support to realize Eternal Sun’s long-term ambitions in a rapidly evolving solar market.

Identifying lead leakage and stability as major challenges for the commercialization of perovskite solar cells (PSCs), researchers from Chongqing University and Huazhong University of Science and Technology have developed a polymerization method to achieve highly stable and environmentally friendly high-performance PSCs. 

Device structure diagram of the PSCs and corresponding cross-sectional SEM image. Image from: Science Advances
 

Through the addition of the small organic molecule N,N′-bis(acryloyl)cystamine (BAC) to the perovskite precursor solution, the terminal alkenes of BAC enable the construction of polymer BAC (PBAC) at the perovskite grain boundaries (GBs) during the annealing process of the perovskite films. PBAC not only overcomes the limitations of organic small molecules but also interacts with perovskites through its numerous functional groups and multiple reactive sites. This interaction effectively passivates deep-level defects, suppressing nonradiative carrier recombination.

Today we have released a new edition of the Perovskites for the Solar Industry market report. This report, over 190 pages long, is a comprehensive guide to next-generation perovskite-based solutions for the solar industry that enable efficient, low cost, lightweight and unique solar solutions. This major new edition includes over 20 new companies and over 50 updates. The perovskite industry is moving fast towards commercialization and our report is a must-read for anyone that wishes to become an expert on this emerging industry and market.

Reading this report, you'll learn all about:

• The perovskite solar industry and market
• The advantages and challenges of perovskite PVs
• Perovskite PV developers and supply chain companies
• What the future holds for the perovskite market and industry

The report also provides:

• Market segmentation by technology, geography, applications and more
• The latest efficiency records (by PV type)
• Details on perovskite collaborative research projects
• A market snapshot and forecast
• Free updates for a year

In the fabrication of FAPbI₃-based perovskite solar cells, Lewis bases play a crucial role in facilitating the formation of the desired photovoltaic α-phase. However, an inherent contradiction in their role is that they must strongly bind to stabilize the intermediate δ-phase, yet weakly bind for rapid removal to enable phase transition and grain growth. 

To address this issue, researchers at the University of Toledo, Northwestern University, Cornell University, University of Washington and Brookhaven National Laboratory have developed a new strategy to control the crystallization process in perovskite-based solar cells, stabilizing the δ-phase while facilitating their transition to the α-phase. Their proposed approach enables the formation of Lewis bases on perovskites on demand to optimize crystallization, which can enhance the efficiency and stability of solar cells.

Researchers at the Hong Kong Polytechnic University (PolyU) and Hong Kong University of Science and Technology (HKUST) have developed an innovative laminated interface microstructure that enhances the stability and photoelectric conversion efficiency of inverted perovskite solar cells.

Prof. ZHOU Yuanyuan, Associate Professor in the Department of Chemical and Biological Engineering (CBE) and Associate Director of the Energy Institute at HKUST, leads a team focused on fundamental research into perovskite optoelectronic devices from a unique structural perspective. They collaborated closely with Prof. CAI Songhua’s team from the Department of Applied Physics at PolyU. Their research revealed that by uniformly creating a “molecular passivation layer-fullerene derivative layer-2D perovskite layer”—a “three-ply” laminated structure on the surface of the perovskite film—they could effectively reduce the density of interface defects and improve energy level alignment. This advancement substantially boosts the photoelectric conversion efficiency of the perovskite solar cell and enhances the durability of the interface under damp-heat and light soaking conditions.

Researchers at NREL, King Abdullah University of Science and Technology (KAUST), Newcastle University, University of Toledo,  Arizona State University and CubicPV have used an ionic salt to replace the fullerene layer in perovskite solar cells, which reportedly boosted their performance, efficiency, and durability.

The researchers said their findings point to a promising approach to advancing perovskite photovoltaic technologies toward commercialization. Kai Zhu, a senior scientist at NREL and an architect of the research effort, said improvements involved changing the chemical composition of the electron transport layer in the perovskite solar cell. This layer is essential as it moves electrons triggered by sunlight through the cell, thereby generating electricity. The fullerene C60 is commonly used for the electron transport layer in inverted perovskite solar cells, but its molecular nature leads to a weak interface and limits the performance of the device. That is especially a problem with long-term stability.

Researchers at Japan's National Institute of Advanced Industrial Science and Technology (AIST) and the UK's University of Oxford have asserted that while perovskite-on-silicon tandem solar cells are highly promising, the intrinsic multilayer device design presents challenges in complexity, which can be a drawback in future mass production. To this end, they developed a TiO_x layer (∼3–5 nm) grown by atomic layer deposition (ALD), that enables a series interconnection of a perovskite n-i-p top cell with a silicon wafer directly. 

A photo of the tandem solar cell fabricated on a 25 mm × 25 mm Si substrate. Image from: Small

The TiO_x layer serves as an all-in-one interconnect, fulfilling the functions of silicon surface passivation, hole extraction from silicon, and recombination junction at the top/bottom cell interface. As a result, a proof-of-concept 22.4%-efficient tandem device was demonstrated. Furthermore, an improved PCE of 26.5% was achieved by capping the TiOx with a thin ALD-TiNy layer (∼4 nm). 

Researchers at Tokyo City University recently developed flexible perovskite/silicon tandem solar cells by fabricating perovskite solar cells atop bendable thin-crystalline silicon solar cells. By reducing the thickness of the silicon substrate to approximately 60 µm, applying microtexturing to its surface, and incorporating a low-refractive index-doped layer, the team produced a flexible silicon heterojunction solar cell with an efficiency exceeding 21%. 

Subsequently, by optimizing the self-assembled monolayer processing conditions on the microtextured surface and constructing an inverted perovskite solar cell on the flexible SHJ, they achieved 26.5% efficiency for the flexible perovskite/silicon tandem solar cell. 

It was reported that a Chinese perovskite manufacturer called Sunshine has completed construction of a MW-scale pilot line for large-area perovskite solar module production. According to local government sources, the project is located in Shushan Economic Development Zone, Hefei, Anhui Province, and is part of Anhui’s key R&D initiative.

The government of Shushan Economic Development Zone states Sunshine has achieved a certified perovskite cell efficiency of 25.05% and developed a 900 cm² perovskite module using its proprietary vapor-assisted printing technology. 

Ultraviolet (UV)-induced damage and limited solar spectrum utilization can hinder the performance of perovskite solar cells (PSCs). In a recent study, researchers from Fuzhou University and Chinese Academy of Sciences developed a thermally activated delayed fluorescent (TADF) molecule, 4CzIPN, to address these challenges. 

Acting as a down-conversion agent, 4CzIPN can convert UV light to visible light via Förster energy transfer, enhancing light absorption and reducing photon loss. Additionally, it can bind Pb²⁺ defects and prevents organic cation degradation through cationic π-effects, stabilizing the perovskite structure. By serving as a crystal growth site, 4CzIPN can promote intermediate phase formation and delay the crystallization process, and improve film quality while mitigating residual stress due to its high thermal expansion coefficient. Furthermore, its UV filtration and hydrophobic properties would reduce perovskite decomposition and device degradation.