November 2017

Researchers at Korea's DGIST have increased the stability and performance of photodiodes using cubic perovskite nanocrystals. The new high-performance photodiodes reportedly reduce thickness to one-sixth of conventional silicon photodiodes, which could be beneficial for fields like autonomous vehicles, military, space exploration and more.

The silicon photodiodes currently in use suffer from limited resolution enhancement due to their thicknesses exceeding 3 micrometers (μm). Perovskite are known to absorbs light well, but until now have been considered difficult to put into practical use in such applications due to low stability. As a way to overcome the disadvantages of the materials, the researchers paid attention to the fact that cesium lead iodide (CsPbI3) perovskite maintains stability in the form of cubic nanocrystals. The research team has developed a new type of thin-film photodiode utilizing cubic cesium lead iodide perovskite nanocrystals and sulfur compounds between the electrodes of the photodiode. The photodiodes developed by the team have improved stability through acid-base reactions between plumbum ions (Pb2 +) and sulfur (S2-) anions.

Researchers at the University of Maryland and ETH Zurich have demonstrated a simple approach for coupling solution-synthesized cesium lead tribromide (CsPbBr₃) perovskite nanocrystals to silicon nitride (SiN) photonic cavities. The reported result is that room temperature light emission is enhanced by an order of magnitude above what perovskites can emit alone.

"Our work shows that it is possible to enhance the spontaneous emission of colloidal perovskite nanocrystals using a photonic cavity," the team said. "Our results provide a path toward compact on-chip light sources with reduced energy consumption and size".

The €5 million CHEOPS project, which officially started in February 2016, aims to develop very low cost but high performing photovoltaic devices based on perovskite technology. CHEOPS is led by Switzerland's Centre Suisse d'Electronique et de Microtechnique (CSEM) and co-funded by the European research and innovation program Horizon 2020. The project will run through January 2019. The list of partnering organizations includes also the University of Oxford, La Universita degli Studi di Roma Tor Vergata, the Fraunhofer Institute for Applied Polymer Research and Oxford Photovoltaics Ltd, among others.

The project recently provided an update on its achievements:

• Dead area of photovoltaic modules decreased to 400µm: Partners in CHEOPS have managed to decrease the break lines ' also known as 'dead area”' of the photovoltaic modules of perovskite solar cells to only 400µm. The breakthrough was achieved by applying optimized laser patterning processes.
• Increased performance of perovskite solar cells thanks to new production processes: CHEOPS researchers have discovered that reducing the thickness of BL-TiO2 from 40-50 nm to 20-30 nm increased the open circuit voltage by 10.36% on average. Experiments also showed that spatial uniformity is key for upscaling perovskite technology.
• Preliminary results of life cycle analysis are positive: CHEOPS researchers have successfully concluded the preliminary life cycle assessment of perovskite/silicon tandem cells. Results show that most of the impact on the use of resources, global warming and energy demand does not stem from the perovskite devices themselves but from the standard Si devices.

In July 2017, Greatcell Solar (formerly Dyesol) announced a plan to raise $5 million AUD (almost $4 million USD) in a share purchase plan. Now, Greatcell announced that it has executed a subscription agreement for a strategic investment of $4 million from an Australian food, water and energy fund. The fund has strongly indicated its interest to maintain its percentage shareholding and, where possible, increase it over time as Greatcell transitions from R&D to global mass manufacture.

The funds will be used to expedite plans to develop Greatcell's prototype facility at CSIRO at Clayton, Victoria and to immediately commence procurement of long lead-time capital equipment required for the prototype facility. These activities are critical and will allow Greatcell to advance technology development and move forward with its Commercialization Schedule relating to glass substrate Perovskite Solar Cells.

Researchers from Penn State and Princeton University have made strides in creating a diode laser based on a perovskite material that can be deposited from solution on a laboratory benchtop.

Organic diode lasers, that are extremely hard to make, are sought after since they have many advantages. First, because organic semiconductors are relatively soft and flexible, organic lasers could be incorporated into new form factors not possible for their inorganic counterparts. While inorganic semiconductor lasers are relatively limited in the wavelengths, or colors, of light they emit, an organic laser can produce any wavelength a chemist cares to synthesize in the lab by tailoring the structure of the organic molecules. This tunability could be very useful in applications ranging from medical diagnostics to environmental sensing.

A team of researchers, that includes researchers from the AMOLF Institute in the Netherlands and Argonne National Laboratory and is led by the University of California San Diego, has observed nanoscale changes in hybrid perovskite crystals that could offer new insights into developing low-cost, high-efficiency solar cells.

Using X-ray beams and lasers, the researchers studied how hybrid perovskites behave at the nanoscale level during operation. Their experiments revealed that when voltage is applied, ions migrate within the material, creating regions that are no longer as efficient at converting light to electricity. "Ion migration hurts the performance of the light absorbing material. Limiting it could be a key to improving the quality of these solar cells," said a member of the Sustainable Power and Energy Center at UC San Diego.

Solliance has achieved a new world record for Perovskite Solar Cell technology demonstrated on industrially applicable Roll-to-Roll (R2R) processes of 13.5% conversion efficiency at cell level. The group stressed that the records were achieved in a factory setting, using an industrially scalable process.

Solliance has achieved the conversion efficiency of 13.5% and module-level aperture area conversion efficiency of 12.2% for perovskite-based photovoltaics using industrially-applicable, roll-to-roll production processes. By further optimizing and re-validating processes that were earlier developed buy Solliance, the performance at both the cell and module level have been improved.

GreatCell Solar, developer of solar technologies, was awarded 700,000 euro (about $825 million USD) in a European Union Horizon 2020 project known as Apolo. The grant to Greatcell's application has occurred through its 100% Italian subsidiary, Greatcell Solar Italy located in Rome, that aims to commercialize perovskite solar technology.

Much of the work involved will investigate advanced technology for higher efficiencies, longer life, and improved encapsulation of PSC-enabled flexible substrates, such as metals and polymers. These are all critical in the successful translation of the 3rd generation PSC photovoltaic (PV) technology from the laboratory to the factory and satisfying PV industry accreditation (IEC 61215).

Researchers from Empa and ETH Zurich have developed a perovskite-based sensor prototype that absorbs light almost optimally and is also cheap to produce.

The team explains that the working mechanism of the human eye, not very different than various image sensors, is based on three different types of sensory cells for the perception of color: cells that are respectively sensitive to red, green and blue alternate in the eye and combine their information to create an overall colored image. However, this mechanism has inherent limitations: as each individual pixel can only absorb a small part of the light spectrum that hits it, a large part of the light is lost. In addition, the sensors used in various applications have basically reached the limits of miniaturization, and unwanted image disturbances can occur; these are known as color moiré effects and have to be removed from the finished image.

Saule Technologies will be presenting a flexible, printed, perovskite photovoltaic module the size of an A4 sheet of paper, for the first time, at the IDTechEx Show on November 15-16th in Santa Clara, CA. The operating Saule module is printed on an ultrathin plastic foil able to charge personal electronic devices, demonstrating one of the many possible applications of these perovskite solar cells. The prototype industry-scale production line is estimated to begin in 2018.

"Scaling up the size of perovskite solar cells is one of the biggest challenges for companies and researchers working with this technology. Printing a stable and operating A4 size module has been among our most important milestones for 2017 and we are more than happy to be able to present it for the first time in the USA," says the CTO and co-founder at Saule Technologies.