Researchers improve perovskite solar cells through novel solvent design

Researchers from Rice University, Northwestern University, Purdue University, University of Washington, CNRS and Argonne National Laboratory have addressed a long-standing issue in making stable, efficient solar panels out of halide perovskites. It took finding the right solvent design to apply a 2D top layer of desired composition and thickness without destroying the 3D bottom one (or vice versa). Such a cell would turn more sunlight into electricity than either layer on its own, with better stability.

The team, led by Chemical and biomolecular engineer Aditya Mohite and his lab at Rice’s George R. Brown School of Engineering, recently reported their success at building thin 3D/2D solar cells that deliver a power conversion efficiency of 24.5%.

Read the full story Posted: Sep 24,2022

Researchers reach 22.31% efficiency of inverted perovskite solar cell using electron-accepting interlayer

Researchers from Korea University and Seoul Women's University have developed an inverted perovskite solar cell by introducing an electron-accepting interlayer at the interface between the perovskite layer and the electron transport layer.

The solar cell has a p-i-n structure (the perovskite cell material is deposited onto the hole transport layer and then coated with the electron transport layer), which is the opposite of the conventional n-i-p device structure. Inverted perovskite solar cells tend to show good stability, but lack in terms of conversion efficiency and cell performance.

Read the full story Posted: Sep 24,2022

Researchers devise new strategy for fabrication of efficient narrow bandgap perovskite films

Researchers at University of North Carolina at Chapell Hill and University of Rochester have developed a novel hot gas-assisted method that could improve the fabrication of narrow bandgap (NBG) perovskite films for tandem solar cells. This strategy, combined with an anti-oxidation material added in the film, could increase the solar cells' carrier recombination lifetime (i.e., the time it takes for excess charge carriers to decay).

The researchers explained that all-perovskite tandem perovskite solar cells have the potential to reduce the cost of photovoltaic systems, due to their potential to reach a higher efficiency than their single-junction counterparts, while maintaining the solution fabrication processes. They said that compared to single junction perovskite modules, the application of tandem structures, which have much smaller photocurrents but higher photovoltage, can also reduce the cell-to-module efficiency derate and enable the realization of higher module efficiencies for monolithically interconnected modules in a series.

Read the full story Posted: Sep 19,2022

Researchers use nanosecond laser to fabricate perovskite solar module with 21.07% efficiency

Scientists from China's Jinan University, CoreTech Integrated Limited and Chinese Academy of Sciences have used selective nanosecond-pulse, laser-induced ablation to create a perovskite solar module with a reduced heat-affected zone.

The team showed that a nanosecond pulse laser can deliver a reduced heat-affected zone due to the small thermal diffusion coefficient (Dt) of the perovskite material, contributing to the accomplishment of a high geometric filling factor  (GFF) of up to 95.5%. In addition, the monolithic interconnection quality was improved by finely lifting off the capping layers on indium tin oxide and identifying the residue within the scribed area. As a result, a certified aperture area efficiency of 21.07% under standard 100 mW cm−2 AM1.5G illumination was achieved with a high photovoltaic fill factor exceeding 80%.

Read the full story Posted: Sep 15,2022

Researchers improve flexible perovskite solar cells with succinate additive

A team of researchers from China's Tsinghua University, National Center for Nanoscience and Technology and Switzerland's Institute of Computational Physics (ICP) of the ZHAW School of Engineering have proposed a strategy to reduce defects and microstrains in perovskite films through multifunctional additives, achieving a record PCE of 23.6% for single-junction flexible perovskite solar cells (FPSCs).

Team develop additive for better flexible perovskite solar cells image

Flexible perovskite solar cells (FPSCs) prepared on flexible substrates, which possess excellent flexibility and a high power-to-weight ratio, hold promise as a power source for wearable electronic devices, aerospace, and building integrated photovoltaics (BIPVs). Further improving the power conversion efficiency (PCE) and bending resistance of flexible devices is key to promoting their practical application.

Read the full story Posted: Sep 12,2022

New carbazole-based hole transporting materials to improve the stability of perovskite solar cells

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.

Read the full story Posted: Sep 08,2022

Researchers use a reactive surface engineering approach to achieve stable and efficient perovskite solar cells

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.

The inverted architecture of this perovskite solar cell, coupled with surface engineering, enabled researchers to improve efficiency and stability. Photo credit: NREL

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.

Read the full story Posted: Sep 03,2022

Researchers design a controllable moisture treatment for perovskite films

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.

Moisture-triggered fast crystallization enables efficient and stable perovskite solar cells image

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.

Read the full story Posted: Aug 26,2022

Researchers develop strategy to improve perovskite absorbers for perovskite solar cells

Researchers at Soochow University, Sichuan University and Empa (Swiss Federal Laboratories for Materials Science and Technology), recently devised a new strategy to create high-quality perovskite absorbers with grains in the micrometer scale and prolonged carrier lifetimes. This new strategy is based on a close-space annealing (CSA) process, a heat-based technique that can be used to change a material's chemical properties.

According to the team, controllable crystallization plays a crucial role in the formation of high-quality perovskites. The researchers reported a universal CSA strategy that increases grain size, enhances crystallinity and prolongs carrier lifetimes in low-bandgap (low-Eg) and wide-bandgap (wide-Eg) perovskite films. The CSA strategy devised by the team is universal, as it can be applied to perovskites with various bandgaps to produce high-quality absorbers with enlarged grains and longer carrier lifetimes. As part of their recent study, the team demonstrated its generalizability by successfully using it to prepare absorbers based on perovskites with different chemical compositions.

Read the full story Posted: Aug 25,2022

Researchers design method to control the properties of perovskite crystals towards efficient perovskite solar cells

Scientists from Taiwan's Industrial Technology Research Institute (ITRI) and National Yang Ming Chaio Tung University recently demonstrated a way to produce high-purity lead-iodide, as a precursor material for a perovskite solar cell. The team used temperature to better control the orientation of crystals, and managed to show much higher efficiencies when the precursor was used to fabricate a perovskite layer and subsequently a working solar cell.

The team worked on the fabrication of lead-iodide (PbI2), an element used in many of the highest-performing perovskite solar cells produced to date. They built on earlier research that has shown the purity and formation of this material could be a key factor in performance once it is integrated into a solar cell. The group’s recent work demonstrates how the crystalline structure and orientation of PbI2 have a significant impact on cell performance. The researchers also introduce a simple way to control this using temperature during synthesis. 

Read the full story Posted: Aug 24,2022