Progress and Challenges Toward Effective Flexible Perovskite Solar Cells

Direct Evidence of the Effect of Water Molecules Position in the Spectroscopy, Dynamics, and Lighting Performance of an Eco-Friendly Mn-Based Organic-Inorganic Metal Halide Material for High-Performance LEDs and Solvent Vapor Sensing

Luminescent Mn(II)-based organic-inorganic hybrid halides have drawn attention as potential materials for sensing and photonics applications. Here, the synthesis and characterization of methylammonium (MA) manganese bromide ((MA)nBrxMn(H2O)2, (n = 1, 4 and x = 3, 6)) with different stoichiometries of the organic cation and inorganic counterpart, are reported. While the Mn2+ centers have an octahedral conformation, the two coordinating water molecules are found either in cis (1) or in trans (2) positions. The photophysical behavior of 1 reflects the luminescence of Mn2+ in an octahedral environment. Although Mn2+ in 2 also has octahedral coordination, at room temperature dual emission bands at ≈530 and ≈660 nm are observed, explained in terms of emission from Mn2+ in tetragonally compressed octahedra and self-trapped excitons (STEs), respectively. Above the room temperature, 2 shows quasi-tetrahedral behavior with intense green emission, while at temperatures below 140 K, another STE band emerges at 570 nm. Time-resolved experiments (77-360 K) provide a clear picture of the excited dynamics. 2 shows rising components due to STEs formation equilibrated at room temperature with their precursors. Finally, the potential of these materials for the fabrication of color-tunable down-converted light-emitting diode (LED) and for detecting polar solvent vapors is shown.

Silane Doping for Efficient Flexible Perovskite Solar Cells with Improved Defect Passivation and Device Stability

In this work, doping 3-amino-propyl triethoxysilane (APTES) into a perovskite precursor is proven to be an effective strategy, which can passivate crystal defects, control the crystallization rate, and improve the morphology. APTES can form oligomers through hydrolysis and a condensation reaction, thus blocking the invasion of external water molecules. In addition, the lone pair electrons on the N atom in the amino group of APTES form a coordination bond with perovskite by sharing the empty 6p orbital on Pb2+, which can effectively passivate the defects of the film and realize a highly uniform and dense perovskite film with preferential crystal growth orientation. The film exhibits high (110) crystal plane orientation and long carrier lifetime and mobility, which improves the performance of flexible perovskite solar cells. Using this approach, the champion device presents an optimal power conversion efficiency of 19.84% with much promoted air stability. Moreover, the efficiency of flexible devices does not decrease after maximum power point irradiation for 360 s.

Structural Decoration of Porphyrin/Phthalocyanine Photovoltaic Materials

Porphyrin/phthalocyanine compounds with fascinating molecular structures have attracted widespread attention in the field of solar cells in recent years. In this review, we focus on the pivotal role of porphyrin and phthalocyanine compounds in enhancing the efficiency of solar cells. The review seamlessly integrates the intricate molecular structures of porphyrins and phthalocyanines with their proficiency in absorbing visible light and facilitating electron transfer, key processes in converting sunlight into electricity. By delving into the nuances of intramolecular regulation, aggregated states, and surface/interface structure manipulation, it elucidates how various levels of molecular modifications enhance solar cell efficiency through improved charge transfer, stability, and overall performance. This comprehensive exploration provides a detailed understanding of the complex relationship between molecular design and solar cell performance, discussing current advancements and potential future applications of these molecules in solar energy technology.

Material and Device Design of Flexible Perovskite Solar Cells for Next-Generation Power Supplies

This review outlines the rapid evolution of flexible perovskite solar cells (f-PSCs) to address the urgent need for alternative energy sources, highlighting their impressive power conversion efficiency, which increases from 2.62% to over 24% within a decade. The unique optoelectronic properties of perovskite materials and their inherent mechanical flexibilities instrumental in the development of f-PSCs are examined. Various strategies proposed for material modification and device optimization significantly enhance efficiency and bending durability. The transition from small-scale devices to large-area photovoltaic modules for diverse applications is discussed in addition to the challenges and innovative solutions related to film uniformity and environmental stability. This review provides succinct yet comprehensive insights into the development of f-PSCs, paving the way for their integration into various applications and highlighting their potential in the renewable energy landscape.