Technical / research - Page 52

Researchers at the UCLA Samueli School of Engineering, along with colleagues from five other universities around the world, have discovered a major reason why perovskite solar cells degrade in sunlight, causing their performance to suffer over time.

The team demonstrated a simple manufacturing adjustment to fix the cause of the degradation, addressing one of the biggest hurdles toward the commercialization of the perovskite-based solar cell technology.

Researchers from Beihang University and the University of Science and Technology of China (USTC) of the Chinese Academy of Science have developed efficient and large-area sky-blue Perovskite-based LEDs, through blade-coating supersaturated precursors.

This approach results in nucleation in the solution phase with much higher nucleation sites, and a faster crystallization rate. The uniform films formed by this method reportedly exhibit smaller grain size, lower trap density, and higher radiative recombination rate.

A new study by HZB, Delft University of Technology, University of Potsdam, Yale University, Czech Academy of Sciences, NIST, University of Würzburg, Nihon University, Oregon State University, University of Warwick, Drexel University and University of California Irvine shows how terahertz (TRTS) and microwave spectroscopy (TRMC) can be used to reliably determine the mobility and lifetime of the charge carriers in semiconducting materials.

Using these measurement data it is possible to predict the potential efficiency of the solar cell in advance and to classify the losses in the finished cell.

An international research group has designed a semi-transparent perovskite solar cell that reportedly shows an improved open-circuit voltage and fill factor thanks to plasmonic enhancement.

The technique is based on the enhancement of the cell's electromagnetic field through metal nanostructures, which improves the device's low optical absorption in the visible spectrum. The research team designed the tech with applications in building-integrated photovoltaics (BIPV) in mind, but it can also be suitable for automotive and smart glasses.

Researchers from France's Institut Photovoltaïque d'Île-de-France (IPVF), EDF R&D and C2N have fabricated a mini perovskite solar module, via deposition of tin oxide as an electron extraction layer using chemical bath deposition (CBD), a low-cost and solution-based fabrication process.

Using this simple low-temperature deposition method, highly homogeneous SnO₂ films can reportedly be made in a reproducible manner. In addition, the perovskite layer was prepared by sequentially slot-die coating on top of the n-type contact. The symbiosis of these two industrially relevant deposition techniques can allow for the growth of high-quality dense perovskite layers with large grains.

Researchers from Germany's Helmholtz-Zentrum Berlin (HZB) and Institute for Solar Energy Research (ISFH) have reported that passivated emitter and rear cell (PERC) tech can be suitable as a basis for tandem cells with perovskite top cells.

PERC cells are usually used in mass production of silicon solar cells, and while the efficiency of the study's tandem cells is still below that of optimized PERC cells alone, the team estimates that it could be increased to up to 29.5% through targeted optimization.

KAUST researchers have developed an artificial electronic retina based on perovskite materials, that can "see" in a similar way to the human vision system and can recognize handwritten digits.

The team designed and fabricated an array of photoreceptors that detect the intensity of visible light via a change in electrical capacitance, mimicking the behavior of the eye's rod retina cells. When the array was connected to an electronic CMOS-sensing circuit and a spiking neural network (a single-layer network with 100 output neurons), it was able to recognize handwritten numbers with an accuracy of around 70%.

Last month, a group of Dartmouth College scientists developed what it refers to as 'the quickest reliable printing method for the manufacturing of perovskite solar cells'. The Dartmouth Engineering Lab's new method accelerates total processing time of solar charge transport layers (CTLs) by 60 times while maintaining reliability.

"Our method prints the layers of the solar cell with the speed and efficiency of a commercial newspaper printing press. This high manufacturing speed is important because it directly translates to lower cost per kWh, which will ultimately make solar energy more affordable for a larger population", said Dartmouth Engineering Professor William Scheideler

Researchers from the Wuhan Institute of Technology and Wuhan University have investigated key factors for realizing high-performance narrow-bandgap Pb-Sn perovskite solar cells (PSCs) via numerical simulations.

The team studied both extrinsic and intrinsic factors of efficient narrow-bandgap Pb-Sn perovskite solar cells. The effects of extrinsic factors on device performance predicted that a p-i-n structure along with appropriate charge transport layers is superior to an n-i-p structure, benefiting from a better energy band alignment. The key intrinsic factors that were studied demonstrated that surface defect density, body defect density, and film thickness of perovskite absorbers play a pivotal role in determining device performance.

Researchers at the University of Rome Tor Vergata's Centre for Hybrid and Organic Solar Energy (CHOSE), collaboration with Greatcell Solar Italy, Technische Universität Dresden and Istituto di Struttura della Materia (ISM-CNR), have designed a way to reduce cell-to-module losses in perovskite solar modules, by optimizing the laser design, establishing a relationship between geometrical fill factor, cell area width, and P1'P2'P3 laser parameters.

In their new work, the research team presented a complete assessment of the optimization of the laser and design of perovskite solar modules. They also transferred these optimizations to a minipanel size, proving the durability of the process.