Tandem

Researchers from China's Wuhan University and South China Normal University have developed a two-terminal (2T) monolithic all-perovskite tandem solar cell that uses a tin-lead (Sn-Pb) perovskite material for the top cell.

The team explained that mixed Sn-Pb perovskites have a narrow bandgap (NBG) of approximately 1.26 eV, which makes them ideal for efficient light harvesting and current-matching with wide bandgap (WBG) subcells in all-perovskite tandem cells.

Researchers at the University of Sydney, Microsolar, University of New South Wales and MiaSolé Hi-Tech Corp. have reported a monolithic perovskite–CIGS tandem solar cell on a flexible conductive steel substrate with an efficiency of 18.1%, the highest for a flexible perovskite–CIGS tandem to date, representing an important step toward flexible perovskite-based tandem photovoltaics.

The advantage of the flexible and conductive steel substrate is that the steel itself can act as both a substrate and an electrode for either large-area-monolithic-panel or smaller-area-singular single-junction or multi-junction cell fabrication.

Researchers at the University of Potsdam, Humboldt-University of Berlin, University of Wuppertal, Swansea University, University of Oxford, East China University of Science and Technology, Friedrich-Alexander-University Erlangen-Nürnberg and HZB have shown that ion-induced field screening is a dominant factor in the operational stability of perovskite solar cells (PSCS). 

The rather poor perovskite stability is usually attributed to electronic defects, electrode oxidation, the ionic nature of the perovskite, or chemical decomposition under moisture and oxygen. Understanding the underlying degradation mechanism is crucial to enable targeted improvements. "In our article, we demonstrate that an increasing concentration of defects in the cells is apparently not a decisive factor for degradation," says Martin Stolterfoht, former leader of the Heisenberg junior research group PotsdamPero at the University of Potsdam and now professor at the Chinese University of Hong Kong.

It was reported that solar production equipment maker Maxwell recently held the groundbreaking ceremony for its HJT perovskite tandem cell equipment facility, located in Wujiang District, Suzhou, Jiangsu Province. 

The company is investing about RMB 5.4 billion ($750.16 million) in the facility focused on research and manufacturing of next-generation HJT perovskite tandem cells. The construction is scheduled to be completed within 2 years.

Researchers at the National University of Singapore (NUS), Beijing University of Technology, Suzhou Maxwell Technologies and Technical University of Munich have developed a triple-junction perovskite/Si tandem solar cell that can reportedly achieve a certified world-record power conversion efficiency of 27.1% across a solar energy absorption area of 1 sq cm, representing the best-performing triple-junction perovskite/Si tandem solar cell thus far. To achieve this, the team engineered a new cyanate-integrated perovskite solar cell that is stable and energy efficient.

Current multi-junction solar cell technologies pose many issues, such as energy loss which leads to low voltage and instability of the device during operation. To overcome these challenges, Assistant Professor at NUS, Hou Yi, led a team of scientists to demonstrate, for the first time, the successful integration of cyanate into a perovskite solar cell to develop a novel triple-junction perovskite/Si tandem solar cell that surpasses the performance of other similar multi-junction solar cells. 

Researchers from Nanjing University, University of Victoria and Australian National University have achieved a high conversion efficiency of 24.5% on large-size all-perovskite tandem solar cells. The result, which the team states is a new world record for the efficiency of all-perovskite tandem solar cells, has reporetdly been confirmed by an international third-party testing institute.

When a lead-tin perovskite is used instead of silicon as the narrow band gap cell in all-perovskite tandem solar cells, the result is often low film quality and device efficiency due to nonuniform nucleation and fast crystallization. In this recent work, the team shows that aminoacetamide hydrochloride can strongly coordinate the precursor components in solution, which homogenizes the crystallization process and also passivates the buried perovskite interface. The authors achieved a certified power conversion efficiency of 24.5% for a 20-square-centimeter module made by blade-coating the layers. 

Researchers from the Korea Institute of Energy Research (KIER), Korea Research Institute of Standards and Science, Jusung Engineering and the Jülich Research Center have reported an advancement in the stability and efficiency of semi-transparent perovskite solar cells.

The semi-transparent solar cells achieved an impressive efficiency of 21.68%, which is said to be the highest efficiency to date among perovskite solar cells that use transparent electrodes. Additionally, they showed remarkable durability, with over 99% of their initial efficiency maintained after 240 hours of operation.

The Dutch government has drafted a public proposal to support the production of heterojunction and perovskite-silicon tandem modules, as well as building- and vehicle-integrated PV panels, with a maximum allocation of €70 million ($75.1 million) per solar manufacturing project. Rijksdienst voor Ondernemend Nederland (RVO), the state-run agency that manages the SDE++ program for renewable energy in the Netherlands, has publicly proposed the idea of supporting the production of solar panels, storage systems and electrolyzers. The new incentive scheme, “Investeringssubsidie maakindustrie klimaatneutrale economie” (IMKE), will fund a portion of the capital expenditure needed to build factories for the three clean energy technologies.

The RVO said that the incentives for the production of PV panels will be limited to products for building-integrated (BIPV) and vehicle-integrated (VIPV) applications, as well as heterojunction modules or perovskite-silicon tandem panels.

In December 2022, CubicPV announced plans to establish 10 GW of conventional mono wafer capacity in the United States. Now, CubicPV said it has halted its plans to build a major U.S. silicon wafer factory, citing a collapse in product prices and soaring construction costs. It was reported that the Company will instead be focusing on producing tandem perovskite solar modules.

As part of its restructuring scheme, the company reduced its workforce and eliminated positions tied to the U.S. factory effort. The Company said it would support the affected workers by providing severance packages and extended health benefits.

Shenzhen Hiking PV has announced plans to set up a joint venture with a state-run investment company to build gigawatt-level perovskite/polysilicon tandem cell and panel production lines in a new factory in Zhongshan, Guangdong province, China. 

The factory is planned to have a total capacity of 7 GW of perovskite/polysilicon tandem cells, with an investment of CNY 5 billion (around USD$700 million). The plan is to build the plant in three phases.