Efficiency - Page 6

Researchers from The Hong Kong University of Science and Technology, Oxford University and the University of Sheffield have developed a molecular treatment that significantly enhances the efficiency and durability of perovskite solar cells. 

A key to the solution was their successful identification of critical parameters that determine the performance and lifespan of halide perovskites. The research team investigated various ways of passivation, a chemical process that reduces the number of defects or mitigates their impact in materials, thereby enhancing the performance and longevity of devices comprising these materials. They focused on the “amino-silane” molecular family for passivating perovskite solar cells.

Researchers from Chung-Ang University, Gwangju Institute of Science and Technology, Hanyang University, The University of Electro-Communications and Chungbuk National University have reported that introducing 4-Phenylthiosemicarbazide (4PTSC) as an additive during the production of tin halide perovskites (Sn-HPs) can boost the performance of perovskite solar cells (PSCs).

Through extensive analyses and experimental comparisons between regular Sn-HP PSCs and those containing the proposed additive, the researchers showcased the multiple functionalities of 4PTSC as an additive. "We purposely chose a multifunctional molecule that acts as a coordination complex and a reducing agent, passivates defect formation, and improves stability," explains Associate Professor Dong-Won Kang from Chung-Ang University, who led the study.

Researchers from China's National Center for Nanoscience and Technology, Chinese Academy of Sciences (CAS) and Beihang University have demonstrated a series of ultrastable Dion−Jacobson (DJ) perovskites for photovoltaic applications. They went on to develop a 2D Dion-Jacobson (DJ) perovskite solar cell that showed high stability while achieving a power conversion efficiency of 19.11%.

Schematic illustration of the blade-coating film and the corresponding device configuration under atmospheric environment at room temperature. Image credit: Nature Communications 

Two-dimensional (2D) Dion-Jacobson (DJ) phase perovskites have drawn attention from academia due to their stability against harsh environmental conditions and their competitive performance in optoelectronic applications. Solar cells based on DJ perovskites, however, have so far shown comparatively poor performance compared to their 3D counterparts.

Researchers from China's Huaqiao University and Qufu Normal University recently introduced new materials that promise to enhance the efficiency of perovskite solar cells (PSCs). Their study details the development of three novel hole transport materials that may improve solar cell performance.

Image credit: Energy Materials and Devices

The team said that the high price of charge transport materials for perovskite solar cells poses a barrier to widespread adoption. Traditional materials like Spiro-OMeTAD are expensive and complex to produce, making it essential to find more affordable alternatives to advance PSC technology and expand its use.

Researchers at MIT have developed a method to synthesize Spiro-MeOTAD, a crucial material for charge transport, without using noble metals. This development led to the creation of a solar cell with 24.2% efficiency, although it demonstrated rapid degradation.

The research team reported that the new method can produce a Spiro-MeOTAD material that remains stable even after 1,400 hours of testing at elevated temperatures (85°C) under continuous one-sun illumination. This durability is critical for materials exposed to the high temperatures and humidity typical of solar panel environments.

The interface between the perovskite layer and electron transporting layer has critical effect on the performance and stability of perovskite solar cells (PSCs). The heterogeneity of the interface critically affects the carrier dynamics at the buried interface. 

To address this, researchers from Tsinghua University, Xiamen University, Chinese Academy of Sciences (CAS) and National Center for Nanoscience and Technology have developed a bridging molecule, (2-aminoethyl)phosphonic acid (AEP), for the modification of SnO₂/perovskite buried interface in n–i–p structure PSCs.

Researchers from China's Yunnan University, University of Science and Technology of China and Southwest United Graduate School have synthesized a new dimethyl acridine-based self-assembled monolayer (SAM), [2-(9,10-dihydro-9,9-dimethylacridine-10-yl)ethyl] phosphonic acid (2PADmA), for use as a hole transport layer in inverted PSCs.

Image credit: Energy Materials and Devices

This novel dimethyl acridine-based SAM, 2PADmA,  when used as a hole-transporting layer in inverted PSCs,  can modulate perovskite crystallization, enhance carrier transport, passivate defects, and reduce nonradiative recombination. The resulting 2PADmA-based devices reportedly achieved a power conversion efficiency (PCE) of 24.01%, significantly higher than the 22.32% PCE of devices using the commonly employed 2PACz SAM. 

The majority of monolithic perovskite/Si tandem solar cells (TSCs) have been built on heterojunction (HJT) Si solar cells, which have seen limited industrial uptake due to manufacturing cost and concern over the viability of metal electrodes and transparent conductive oxides (TCOs) incorporating expensive elements. Recently, researchers from The Australian National University, University of Melbourne and University of New South Wales demonstrated that high efficiencies of perovskite/Si TSCs can be achieved with Si bottom cells based on a double-side poly-Si/Si dioxide (SiO₂) passivating contact (poly-Si cell) without silver or transparent conductive oxides (TCOs), fabricated using mass-production techniques. 

In addition, a novel low-absorption, dopant-free bilayer-structured hole transport layer (HTL) composed of ultra-thin poly(N,N′-bis-4-butylphenyl-N,N′-bisphenyl)benzidine (Poly-TPD) and 2,2′,7,7′-tetra(N,N-di-p-tolyl)amino-9,9-spirobifluorene (Spiro-TTB) double layers was developed for the perovskite top cell, which passivates the perovskite surface and enhances the near-interface conductivity, thus increasing the open-circuit voltage and fill factor. 

Researchers at Hong Kong Baptist University, The Hong Kong University of Science and Technology (HKUST) and Yale University have revealed the existence of surface concavities on individual crystal grains that are the fundamental blocks of perovskite thin films, and examined their significant effects on the film properties and reliability. 

Based on this discovery, the team designed a new way of making perovskite solar cells (PSCs) more efficient and stable via a chemo-elimination of these grain surface concavities.

Singapore-based startup Singfilm Solar has announced it achieved a power conversion efficiency of 22.6% for a p-i-n structure perovskite solar panel. The result was said to be confirmed by China's National PV Industry Measurement and Testing Center (NPVM). 

The design of the mini modules includes eight sub-cells connected in series on a 55 mm × 55 mm substrate, each sub-cell with a width of 5.6 mm. Each sub-cell within the module reportedly demonstrates impressive performance metrics with an open-circuit voltage of 1.169 V, a short-circuit current of 25 mA/cm², and a fill factor of 77.4%.