Efficiency - Page 20

Printable planar carbon electrodes are emerging as a promising replacement for thermally evaporated metals as the rear contact for perovskite solar cells (PSCs). However, the power conversion efficiencies (PCEs) of the state-of-the-art carbon-electrode PSC (c-PSC) noticeably lag behind their metal-electrode counterparts. Recently, researchers from Friedrich-Alexander-Universität Erlangen-Nürnberg have proposed a hole-transporting bilayer (HTbL) configuration to improve the fill factor and the open-circuit voltage of carbon electrode PSCs (c-PSCs). 

The HTbL was prepared by sequentially blade coating two organic semiconductors between perovskite and carbon, with the outer HTL enhancing hole extraction to carbon, while the inner HTL mitigates perovskite surface recombination. Consequently, the fully printed c-PSCs with HTbL outperformed those with single HTL, and a stabilized champion PCE of 19.2% was achieved compared with that of 17.3%. 

The following is a sponsored post by MBRAUN

Germany-based inert gas leading solutions provider MBRAUN is offering a wide range of solutions for the perovskite industry, ranging from R&D systems to full-industrial solutions. One of the company’s customers, KAUST University in Saudi Arabia, recently announced a word record with the help of MBRAUN systems.

Erkan Aydin, Professor and Researcher Scientist at KAUST, says: “In two months' time, we've set a new world record for perovskite/silicon tandem solar cells - again! With our latest update, perovskite/silicon tandem solar cells have reached impressive 33.7% certified power conversion efficiency, surpassing our previous milestone of 33.2%. We hope that our new achievement will contribute to accelerating the green energy transition. The recent champion cell was certified at European Solar Test Installation (ESTI) Center.”

New efficiency world record, June 2023

Only in the beginning of April, researchers from the KAUST Photovoltaic Laboratory (KPV-Lab) at the KAUST Solar Center produced a perovskite/silicon tandem solar cell with a power conversion efficiency (PCE) of 33.2 %, topping the world record recently set by the Helmholtz-Zentrum Berlin (HZB).

A team of researchers at the National Centre for Photovoltaic Research and Education (NCPRE) at the Indian Institute of Technology Bombay (IITB) has fabricated a semi-transparent perovskite solar cell (PSC) that, by combining it with a silicon-based solar cell, has demonstrated an efficiency of more than 26% for such a cell.

The team at IIT Bombay has addressed the stability issue by combining their PSC with a silicon solar cell in a tandem configuration. Combining the two different types of solar cells allows the device to convert more of the light falling on it into electricity. Apart from the higher efficiency, the tandem architecture also provides greater stability to the device, while driving its overall lifetime costs low.

Researchers from Northern Illinois University, National Renewable Energy Laboratory (NREL), Northwestern University and Argonne National Laboratory have reported a bilayer back electrode configuration consisting of an Ni-doped natural graphite layer with a fusible Bi-In alloy. This back electrode can be deposited in a vacuum-free approach and enables perovskite solar cells (PSCs) with a power conversion efficiency of 21.0%. These inexpensive materials and facile ambient fabrication techniques can help provide an appealing solution to low-cost PSC industrialization.

A thin layer of gold or silver can help improve the efficiency of perovskite solar cells, but the researchers have found a less expensive material that will enable commercialization of the technology without exorbitant cost.  “A layer of gold in a solar panel or even a layer of silver is probably too expensive,” said Kai Zhu, a senior scientist in the Chemistry and Nanoscience Center at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL). “It would make the solar panel not affordable for most people.”

Researchers at the National University of Singapore (NUS) and Solar Energy Research Institute of Singapore (SERIS) have announced achieving 24.35% efficiency for self-designed inverted perovskite solar cells on an active area of 1 cm² , saying it is an improvement over the previous record high of 23.7% on the same area.

To get to this 24.35% efficiency level, the team says it incorporated a novel interface material into perovskite cells that contributed a ‘range of advantageous attributes’. These include excellent optical, electrical and chemical properties that enhanced both their efficiency and longevity.

An international team has designed a perovskite solar cell with an electron transport layer (ETL) made of indium sulfide (In₂S₃) that could reportedly reduce the defect density in the device.

The scientists used a numerical module and the SCAPS-1D solar cell capacitance software, which is a simulation tool for thin-film solar cells that was developed by the University of Ghent in Belgium, to simulate s solar cell based on methylammonium lead iodide (MAPbI₃).

LONGi announced new conversion efficiency of 33.5% for silicon-perovskite tandem solar cells based on commercial CZ silicon wafers, as was revealed at the Intersolar Europe 2023 exhibition. Earlier this month, LONGi announced its “STAR Innovative Ecological Cooperation Platform” and its newly achieved efficiency of 31.8% for perovskite/crystalline silicon tandem solar cells based on commercial CZ silicon wafers.

“Improving cell conversion efficiency and reducing the cost of electricity remain the perpetual theme driving the development of the photovoltaic industry.” Said Li Zhenguo, President of LONGi.

Researchers China's Nanjing University, University of Science and technology of China and Chinese Academy of Sciences (CAS) have fabricated an all-perovskite tandem solar cell that is said to show lower interfacial non-radiative recombination and improved charge extraction.

All-perovskite tandem cells could have efficiencies similar to those of tandem perovskite-silicon devices, but with better flexibility, lighter weight, and a lower environmental impact than technologies relying on silicon wafers. The research team explained that their all-perovskite tandem solar cells can be used in power station power generation, rooftop photovoltaic, water catalytic decomposition, carbon dioxide catalytic decomposition, and space applications due to their high open circuit voltage and high efficiency.

Researchers from the CEA at INES, ENEL Green Power and its subsidiary 3SUN in Catania, are developing tandem perovskite technology on silicon with two terminals to achieve the highest yields that can be industrialized as quickly as possible. They have announced a new record for a PIN architecture cell with a conversion efficiency of 27.1% on 9 cm² with shading correction.

The CEA and 3SUN had previously reported results of 26.5%, for the same tandem cell of PIN architecture on 9cm² and with shading correction. The device with an active area of ​​9 cm² has a Voc greater than 1900 mV. 

Researchers from Purdue University, University of California and the University of Kentucky have constructed a new perovskite interlayer that reportedly exhibits both superior thermal and moisture stability in ambient conditions.

“Enhancing the stability and lifetime of perovskite devices is necessary in order to realize the goal of commercialization for perovskite photovoltaics,” said Jiaonan Sun. “Today, the stability of commonly used hole transporting layers (HTL) is still a bottleneck for achieving the required lifetime". Poly(triaryl amine) (PTAA) is a promising polymeric hole transporting material used in PSC applications, however, it’s hydrophobicity causes problematic interfacial contact with perovskite, limiting the device’s performance. Led by Dr. Letian Dou, the researchers successfully constructed a uniform two-dimensional (2D) perovskite interlayer with conjugated ligands, between three-dimensional (3D) perovskites and PTAA to improve the power conversion efficiency and the interfacial adhesion of the devices. These increased-ion migration, energy barrier conformal, 2D coated unencapsulated devices with new ligands provide greater thermal and moisture stability in different environments.