The Perovskite-Info newsletter (February 8, 2022)

Researchers from the Australian National University (ANU), China's Sun Yat-sen University and Chinese Academy of Sciences (CAS) have reportedly set a new record conversion efficiency for perovskite-based solar cells, improving on a record they already held.

The recent research details how a solar conversion efficiency of 22.6% for a one square centimeter cell was achieved through improvements on previous perovskite solar cells.

This is a sponsored article by Solaires

Solaires Entreprises Inc., a Canadian solar energy startup based in Victoria, B.C. has developed the most stable and versatile perovskite-based photovoltaic ink with the longest shelf life available in the market.

Current perovskite inks available in the market are only suitable for research and small-scale coating processes. They lack the stability and shelf life required for the large-scale manufacturing of perovskite solar panels, particularly for air-processed device fabrication.

Tin (Sn)-based metal halide perovskites (MHPs) could be an environmentally benign alternative to lead-based ones, which are toxic. However, some critical issues need to be resolved before Sn-based MHPs can be leveraged in planar semiconductor devices. When arranged into a 2D structure (or quasi-2D structure with a few layers), defects in the crystal structure of Sn-based MHPs called “grain boundaries” hamper the mobility of charge carriers throughout the material. If used in a TFT, this phenomenon results in a large series resistance that ultimately degrades performance. In addition, a TFT made using an Sn-based MHP arranged into a 3D structure faces a problem of extremely high carrier density of the 3D material, that causes the transistor to be permanently ON unless very high voltages are applied.

Scientists from Tokyo Tech, National Institute for Materials Science and Silvaco Japan have proposed a novel concept based on a hybrid structure for Sn-based metal halide perovskites (MHPs), called the “2D/3D core–shell structure.” In this structure, 3D MHP cores are fully isolated from one another and connected only through short 2D MHP strips (or “shells”). This alternating arrangement manages to address both these issues, according to the team.

Scientists from the Xi’an Jiaotong University, Chinese Academy of Science and City University of Hong Kong have reported the fabrication of a highly stable perovskite solar cell by capping the photoactive layer with low-dimensional (LD) perovskitoids.

Atomic structure of (A) (p-PBA)Pb2I6 (1D) and (B) (m-PBA)2PbI6 (0D). Image from study

“Perovskitoids have the potential to effectively modify 3D perovskite due to its diverse PbI₆ connection styles and high stability,” the researchers stated, referring to the properties of the 1D and 0D capping layer materials used for 3D perovskite (m-PBA)₂PbI₆. “Both 1D and 0D perovskitoids have intrinsically low defect densities and can withstand relatively high lattice strains; thus, they can serve as blocking channels for undesired Shockley-Read-Hall recombination and material degradation.”

Scientists from Nankai University in China have developed an integrated solar rechargeable zinc battery (SRZB), powered by perovskite solar cells, that could be used for wearable smart electronics, Internet of Things (IoT) devices, and other electrically powered equipment.

The device consists of a perovskite solar cell part and a rechargeable aqueous zinc metal cell, which are combined via a sandwich joint electrode. Image from study

The system has a 4-layer configuration including a perovskite light absorber, a sandwich joint electrode, an aqueous alkaline electrolyte, and zinc metal. “Benefiting from the integrated device structure, specially designed components and narrow-range voltage-matching mechanism, our inexpensive SRZB shows remarkably high specific energy, high specific power, high safety and high overall efficiency,” the researchers said.