Lattice Mismatch at the Heterojunction of Perovskite Solar Cells.

Lattice mismatch significantly influences microscopic transport in semiconducting devices, affecting interfacial charge behavior and device efficacy. This atomic-level disordering, often overlooked in previous research, is crucial for device efficiency and lifetime. Recent studies have highlighted emerging challenges related to lattice mismatch in perovskite solar cells, especially at heterojunctions, revealing issues like severe tensile stress, increased ion migration, and reduced carrier mobility. This review systematically discusses the effects of lattice mismatch on strain, material stability, and carrier dynamics. It also includes detailed characterizations of these phenomena and summarizes the current strategies including epitaxial growth and buffer layer, as well as explores future solutions to mitigate mismatch-induced issues. We also provide the challenges and prospects for lattice mismatch, aiming to enhance the efficiency and stability of perovskite solar cells, and contribute to renewable energy technology advancements.

A-D-A Molecule-Bridge Interface for Efficient Perovskite Solar Cells and Modules.

As the photovoltaic field endeavors to transition perovskite solar cells (PSCs) to industrial applications, inverted PSCs, which incorporate fullerene as electron transport layers, have emerged as a compelling choice due to their augmented stability and cost-effectiveness. However, these attributes suffer from performance issues stemming from suboptimal electrical characteristics at the perovskite/fullerene interface. To surmount these hurdles, an interface bridging strategy (IBS) is proposed to attenuate the interface energy loss and enhance the interfacial stability by designing a series of A-D-A type perylene monoimide (PMI) derivatives with multifaceted advantages. In addition to passivating defects, the IBS plays a crucial role in facilitating the binding between perovskite and fullerene, thereby enhancing interface coupling and importantly, improving the formation of fullerene films. The PMI derivatives, functioning as bridges, serve as a protective barrier to enhance the device stability. Consequently, the IBS enables a remarkable efficiency of 24.62% for lab-scale PSCs and an efficiency of 18.73% for perovskite solar modules craft on 156 × 156 mm2 substrates. The obtained efficiencies represent some of the highest recorded for fullerene-based devices, showcasing significant progress in designing interfacial molecules at the perovskite/fullerene interface and offering a promising path to enhance the commercial viability of PSCs.

Mechanical Durability and Flexibility in Perovskite Photovoltaics: Advancements and Applications.

The remarkable progress in perovskite solar cell (PSC) technology has witnessed a remarkable leap in efficiency within the past decade. As this technology continues to mature, flexible PSCs (F-PSCs) are emerging as pivotal components for a wide array of applications, spanning from powering portable electronics and wearable devices to integrating seamlessly into electronic textiles and large-scale industrial roofing. F-PSCs characterized by their lightweight, mechanical flexibility, and adaptability for cost-effective roll-to-roll manufacturing, hold immense commercial potential. However, the persistent concerns regarding the overall stability and mechanical robustness of these devices loom large. This comprehensive review delves into recent strides made in enhancing the mechanical stability of F-PSCs. It covers a spectrum of crucial aspects, encompassing perovskite material optimization, precise crystal grain regulation, film quality enhancement, strategic interface engineering, innovational developed flexible transparent electrodes, judicious substrate selection, and the integration of various functional layers. By collating and analyzing these dedicated research endeavors, this review illuminates the current landscape of progress in addressing the challenges surrounding mechanical stability. Furthermore, it provides valuable insights into the persistent obstacles and bottlenecks that demand attention and innovative solutions in the field of F-PSCs.

Surface modulation for highly efficient and stable perovskite solar cells.

Defects formed by halide ion escape and wettability of the perovskite absorber are essential limiting factors in achieving high performance of perovskite solar cells (PSCs). Herein, a series of ionic organic modulators are designed to contain halide anions to prevent defect formation and improve the surface tension of the perovskite absorber. It was found that the surface modulator containing Br anions is the most effective one due to its capability in bonding with the undercoordinated Pb2+ ions to reduce charge recombination. Moreover, this surface modulator effectively creates a suitable energy level between the perovskite and hole transport layer to promote carrier transfer. In addition, the surface modulator forms a chemisorbed capping layer on the perovskite surface to improve its hydrophobicity. As a result, the efficiency of PSCs based on surface modulators containing Br anion enhances to 23.32% from 21.08% of the control device. The efficiency of unencapsulated PSCs with a surface modulator retains 75.42% of its initial value under about 35% humidity stored in the air for 28 days, while the control device only maintained 44.49% of its initial efficiency. The excellent stability originates from the hydrophobic perovskite surface after capping the surface modulator.