Stability - Page 15

Researchers from China's Huazhong University of Science and Technology and Singapore's National University of Singapore have introduced an eco-friendly and low-cost organic polymer, cellulose acetate butyrate (CAB), to the grain boundaries and surfaces of perovskites, resulting in a high-quality and low-defect perovskite film with a nearly tenfold improvement in carrier lifetime.

The CAB-treated perovskite films have a well-matched energy level with the charge transport layers, thus suppressing carrier nonradiative recombination and carrier accumulation. As a result, the optimized CAB-based device achieved a champion efficiency of 21.5% compared to the control device (18.2%).

Researchers from Japan-based National Institute for Materials Science (NIMS) recently developed a durable 1cm² perovskite solar cell capable of generating electricity for more than 1,000 continuous hours at a photoelectric conversion efficiency (i.e., power generation efficiency) of more than 20% in exposure to sunlight.

As this solar cell can be fabricated on the surface of a plastic material at approximately 100°C, this technique could have great potential for developing light, versatile solar cells.

Researchers from Israel's Bar-Ilan University and Weizmann Inst. of Science have measured the effect of humidity on hardness and elastic modulus (E) for two series of lead halide perovskite single crystals. The results indicated the influence of hydrogen (H)-bonding, bond length, and polarization of the ions in lead halide perovskite single crystals.

The team detected an inverse relation between hardness and modulus, which was strengthened with increased humidity. Their findings shed light on the material's distinct structure and properties at the atomic scale. The conclusion of this work was based on the evaluation of outcomes of various nano-indentation techniques that differentiated between surface and bulk E and explored different manifestations of hardness.

Scientists from King Abdullah University of Science and Technology (KAUST) and Solar Energy Research Institute of Singapore (SERIS) have examined the potential-induced degradation (PID) susceptibility of perovskite-silicon tandem devices fabricated in their lab. They exposed tandem cell devices to PID stress and found that they lost as much as 50% of their initial performance after just one day. This led the team to assess that more work needs to be done on the issue before perovskites can be commercialized and deployed at scale.

Research on perovskite solar cells' stability challenges has largely focused on the material’s sensitivity to moisture, high temperatures, and other environmental conditions. Potential-induced degradation (PID), caused by currents leaking from the cell and driving various damaging mechanisms, has long been a threat to performance in silicon PV modules, but has so far been much less explored in emerging PV technologies such as perovskite.

Scientists from Kaunas University of Technology and Vilnius University in Lithuania and University of Colorado in the U.S have proposed a method for increasing the stability and performance of perovskite solar cells. The team synthesized a new class of carbazole-based cross-linkable materials, which are resistant to various environmental effects, including strong solvents used in the production of solar cells.

When applied as hole transporting layers, the new materials helped achieve the 16.9% efficiency of the inverted-architecture perovskite cells at the first attempt. It is expected to reach higher efficiency upon optimization.

Researchers at the U.S. Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL), in collaboration with scientists from the University of Toledo, the University of Colorado–Boulder, and the University of California–San Diego, have announced a technological breakthrough and constructed a perovskite solar cell with the dual benefits of being both highly efficient and highly stable.

A unique architectural structure enabled the researchers to record a certified stabilized efficiency of 24% under 1-sun illumination, making it the highest reported of its kind. The highly efficient cell also retained 87% of its original efficiency after 2,400 hours of operation at 55 degrees Celsius.

Scientists from China's Huaqiao University and Henan Normal University have developed a controllable moisture treatment for perovskite films that can promote the mass transportation of organic salts. The films were used to fabricate a 0.2 cm² perovskite solar cell that was able to retain 80% of its initial efficiency after 1200 h.

The group investigated the effects of moisture in the air on the intermediate and final perovskite films in solar cells and developed the controllable moisture treatment that relies on a series of nitrogen (N₂)-protected characterization techniques.

Sweden-based Evolar, which has developed a unique perovskite-based solar cell technology, has announced that it can now present results from climate tests that show at least 25 years lifespan with stable electricity yield.

Evolar's tandem technology reportedly provides 25% more electricity at a low cost. However, to be commercially ready, solar panels also need to have a guaranteed lifespan of at least 25 years with stable electricity generation throughout this period.

Perovskite LEDs can be produced quite easily and at low cost. They show great promise as they are lightweight and can offer flexibility compared to OLEDs, with color purity and tunability similar to LEDs based on III-V semiconductors. However, the poor device stability of perovskite LEDs will have to be overcome before commercial applications can emerge. Typical lifespans of perovskite LEDs are on the order of 10 to 100 hours. In contrast, the minimum lifetime required for an OLED display is 10,000 hours. It is currently challenging to reach this threshold, as halide perovskite semiconductors can be intrinsically unstable due to the ionic nature of their crystal structures—the ions can move around when voltages are applied to the LEDs, leading to material degradation.

In their recent work, a research group led by Prof. Di Dawei and Prof. Zhao Baodan at the College of Optical Science and Engineering of Zhejiang University discovered that by using a dipolar molecular stabilizer, it is possible to make efficient and stable perovskite LEDs with ultralong lifetimes, satisfying the demands of commercial applications. The research was carried out in collaboration with the research groups of Prof. Li Cheng at Xiamen University, Prof. Hong Zijian at Zhejiang University, and Prof. Li Weiwei at NUAA and formerly at Cambridge University. 

Sekisui Chemical has announced that it will provide and install film-type perovskite solar cells to Umekita (Osaka) Station, to be developed by West Japan Railway Company.

The Company claims it has achieved outdoor durability of 10 years equivalent by means of original “sealing, film formation, materials and process technology,” creating a 30 cm-wide roll-to-roll manufacturing process. This manufacturing process has been successfully used to produce film-type perovskite solar cells with power generation efficiency of 15.0%. Currently, work is aiming to establish a manufacturing process for 1 m-wide rolls that offers more improvements in durability and power generation efficiency with a view to practical application and the New Energy and Industrial Technology Development Organization (NEDO) Green Innovation Fund is being leveraged to speed up development.