Nanowerk October 4, 2024 All-inorganic CsPbI3 perovskite quantum dots (PQDs) hold significant potential for next-generation photovoltaics due to their unique optoelectronic properties. Initially used long-chain ligands in PQDs synthesis stabilized the black phase but hindered charge transport when employed to solar cells, necessitating their replacement with shorter ones leading to the formation of surface defects and loss of tensile strain, resulting in the transition to the undesired orthorhombic phase and compromising PQD solar cell performance. To address these issues researchers at the Republic of Korea developed an efficient ligand-exchange process utilizing a multifaceted anchoring ligand, 2-thiophenemethylammonium iodide (ThMAI). The larger […]
Category Archives: Solar cells
First flexible perovskite solar cells on polycarbonate films
Nanowerk September 14, 2024 Despite its widespread use in many applications, poor chemical resistance and roughness of polycarbonate (PC) has hindered its adoption as a substrate in solar cell technologies. An international team of researchers (Italy, Germany, Iran) developed a solution-processed planarizing layer using a commercial ambient-curable refractory resin through blade coating. Blade coating decreased film roughness from 1.46 µm to 23 nm, lowered water vapor transmission rates (WVTR) by a half, and significantly improved solvent resistance enabling deposition of precursor inks. The power conversion efficiency (PCE) reached 13.0%. The unencapsulated PSCs retained 80% of initial PCE after 1776 h […]
Small steps for electrons—big steps for the future? Ultrafast microscope reveals electron pathways in solar cells
Phys.org July 17, 2024 To understand the transport of photoexcited charge carriers for designing next-generation light-harvesting devices an international team of researchers (Germany, UK) simultaneously probed the intrinsic out-of-plane charge-carrier diffusion and the nanoscale morphology of the organic–inorganic metal halide perovskite FA0.83Cs0.17Pb(I1−xClx)3 by pushing depth-sensitive terahertz near-field nanospectroscopy to extreme subcycle timescales. By analysing deep-subcycle time shifts of the scattered terahertz waveform after photoexcitation, they accessed the vertical charge-carrier dynamics within single grains. At all the measured locations, despite topographic irregularities, diffusion was homogeneous on the 100 nm scale, although it varied between mesoscopic regions. According to the researchers linking in […]
A solar cell you can bend and soak in water
RIKEN Research March 27, 2024 Waterproofing ultra flexible organic photovoltaics without compromising mechanical flexibility and conformability remains challenging. An international team of researchers (Japan, USA – Georgia Institute of Technology) demonstrated waterproof and ultra flexible organic photovoltaics through the in-situ growth of a hole-transporting layer to strengthen interface adhesion between the active layer and anode by depositing silver electrode directly on top of the active layers, followed by thermal annealing treatment. The in-situ grown hole-transporting layer exhibited higher thermodynamic adhesion between the active layers, resulting in better waterproof. The 3 μm-thick organic photovoltaics retained 89% and 96% of their pristine performance […]
Researchers take major step toward developing next-generation solar cells
Science Daily March 22, 2024 The efficiency of p–i–n perovskite solar cells fabricated in air still lags behind those made in an inert atmosphere. An international team of researchers (China, USA-University of Colorado) introduced an ionic pair stabilizer, dimethylammonium formate (DMAFo), into the perovskite precursor solution to prevent the degradation of perovskite precursors. It inhibited the oxidization of iodide ions and deprotonation of organic cations, improved the crystallinity and reduced defects in the resulting perovskite films. They showed the generation of additional p-type defects during ambient air fabrication that suggested the need for improving bulk properties of the perovskite film […]
Researchers develop world’s most efficient quantum dot solar cell
Nanowerk February 21, 2024 Research has predominantly focused on inorganic cation perovskite-based colloidal quantum dots (PQDs) even though organic cation PQDs have more favorable bandgaps. Researchers in South Korea developed solar cells using narrow bandgap organic cation based PQDs and demonstrated substantially higher efficiency compared with their inorganic counterparts. They employed an alkyl ammonium iodide-based ligand exchange strategy, which proved to be substantially more efficient in replacing the long-chain oleyl ligands than conventional methyl acetate-based ligand exchange while stabilizing the α phase of organic PQDs in ambient conditions. They showed a solar cell with the organic cation PQDs with high […]
One-atom-thick ribbons could improve batteries, solar cells and sensors
Science Daily September 21, 2023 Quasi-1D nanoribbons provide a unique route to diversifying the properties of their parent 2D nanomaterial, introducing lateral quantum confinement and an abundance of edge sites. Phosphorus-only materials do not conduct electricity very well, hindering their use for certain applications. Researchers in the UK created a new family of nanomaterials with the creation of arsenic–phosphorus alloy nanoribbons (AsPNRs). By ionically etching the layered crystal black arsenic–phosphorus using lithium electride followed by dissolution in amidic solvents, solutions of AsPNRs were formed. The ribbons were typically few-layered, several micrometers long with widths tens of nanometers across, and both […]
Linking two solar technologies is a win-win for efficiency and stability
Nanowerk September 5, 2023 Although metal halide perovskites have rapidly enabled a range of high-performance photovoltaic technologies, their catastrophic failure under reverse voltage bias poses a roadblock for their commercialization. An international team of researchers (Princeton University, Saudi Arabia) conducted a series of stress tests to compare the reverse-bias stability of perovskite single-junction, silicon single-junction, and monolithic perovskite/silicon tandem solar cells. They demonstrated that the tested perovskite/silicon tandem devices were considerably more resilient against reverse bias compared with perovskite single-junction devices. The origin of such improved stability stemmed from the low reverse-bias diode current of the silicon subcell. This translated […]
Ammonium is the secret ingredient in stable, efficient & scalable perovskite solar cells
EurekAlert December 20, 2022 Controlling the crystallization process of perovskite thin films to obtain a high-quality material is one of the most challenging aspects for upscaling perovskite solar cell (PSC) technology. However, to date, lead acetate has been used exclusively as a precursor for the synthesis of methylammonium (MA) or cesium (Cs) based perovskites, which are unstable and less efficient. Researchers in Australia produced high-quality large-area formamidinium–caesium mixed-cation perovskite films by blade-coating a lead acetate-based precursor formulation in an ambient laboratory environment, with the use of NH4+ as a volatile cation to drive off acetate during annealing, leading to formation […]
Ultrathin solar cells promise improved satellite performance
Nanowerk November 8, 2022 Ultra-thin solar cells’ radiation tolerance may allow them to be used in harsh radiation environments, where thicker cells would degrade rapidly. Researchers in the UK irradiated devices with an 80 nm GaAs absorber layer with 3 MeV protons. They mapped the introduction of radiation-induced defects with increasing proton fluence and characterized a decrease in carrier lifetime after irradiation fluence. Despite the substantial reduction in carrier lifetime, short-circuit current did not degrade up to a proton fluence of 1 × 1015 cm−2, beyond which the short-circuit current collapsed. The exposure correlated with the point at which the carrier lifetime became comparable to […]