The Perovskite-Info newsletter (March 1, 2022)

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.

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 at the Chinese Academy of Sciences (CAS) and Beihang University have developed an approach to fabricate perovskite solar cells based on a solution printing strategy for meniscus-assisted-coating (MAC).

The strategy was proposed for preparing high-quality blend films with an optimized morphology of the active layer. The efficiency of as-prepared all-PSCs was reported to be 15.53% from MAC, higher than that of cells prepared by the conventional spin coating (SC) method (14.58%), owing to the more ordered molecular packing and better nanofiber interpenetrating network structure for active layer prepared by MAC.

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%.

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.

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.