RACGAP1 promotes lung cancer cell proliferation through the PI3K/AKT signaling pathway.

We aimed to investigate the expression and clinic significance of Rac GTPase Activating Protein 1 (RACGAP1) in human lung adenocarcinoma (LUAD). Online database analysis revealed a significant increase in RACGAP1 mRNA expression among 26 types of tumor tissues, including LUAD tissues. Online database and tissue microarray analyses indicated that RACGAP1 expression was significantly upregulated in LUAD tissues. Genetic variation analysis identified four different genetic variations of RACGAPs in LUAD. Moreover, online database analysis showed that RACGAP1 upregulation was correlated with shorter survival in patients with LUAD. After silencing RACGAP1 expression in A549 cells using siRNA and assessing its protein levels via Western blotting, we found that RACGAP1 knockdown inhibited cell growth and induced apoptosis determined using the Cell Counting Kit-8 assay, colony formation assay, and flow cytometry. Mechanistically, western blot analysis indicated that Bax expression increased, whereas Bcl-2 expression decreased. Moreover, RACGAP1 knockdown attenuated PI3K/AKT pathway activation in lung cancer cells. Taken together, our findings showed that RACGAP1 was overexpressed in LUAD tissues and played an important role in lung cancer by increasing cell growth through the PI3K/AKT signaling pathway. This study suggests recommends evaluating RACGAP1 in clinical settings as a novel biomarker and potential therapeutic target for lung cancer.

Efficient and Stable Perovskite Solar Modules Enabled by Inhibited Escape of Volatile Species.

The intrinsically weak bonding structure in halide perovskite materials makes components in the thin films volatile, leading to the decomposition of halide perovskite materials. The reactions within the perovskite film are reversible provided that components do not escape the thin films. Here, a holistic approach is reported to improve the efficiency and stability of PSMs by preventing the effusion of volatile components. Specifically, a method for in situ generation of channel barrier layers for perovskite photovoltaic modules is developed. The resulting PSMs attain a certified aperture PCE of 21.37%, and possess remarkable continuous operation stability for maximum power point tracking (MPPT) of T90 > 1100 h in ambient air, and damp heat (DH) tracking of T93 > 1400 h.

Dendrimer Modification Strategy Based on the Understanding of the Photovoltaic Mechanism of a Perovskite Device under Full Sun and Indoor Light.

The wide-band-gap inorganic CsPbI2Br perovskite material provides a highly matched absorption range with the indoor light spectrum and is expected to be used in the fabrication of highly efficient indoor photovoltaic cells (IPVs) and self-powered low-power Internet of Things (IoT) sensors. However, the defects that cause nonradiative recombination and ion migration are assumed to form leakage loss channels, resulting in a severe impact on the open-circuit voltage (VOC) and the fill factor (FF) of IPVs. Herein, we introduce poly(amidoamine) (PAMAM) dendrimers with multiple passivation sites to fully repair the leakage channels in the devices, taking into account the characteristics of IPVs that are extremely sensitive to nonradiative recombination and shunt resistance. The as-optimized IPVs demonstrate a promising PCE of 35.71% under a fluorescent light source (1000 lux), with VOC increased from 0.99 to 1.06 V and FF improved from 75.21 to 84.39%. The present work provides insight into the photovoltaic mechanism of perovskites under full sun and indoor light, which provides guidance for perovskite photovoltaic technology with industrialization prospects.

FA cation replenishment-induced second growth of printed MA-free perovskites for efficient solar cells and modules.

Printing is one industrially compatible scalable method for the preparation of perovskite thin films but suffers from a low nucleation rate that causes an inferior crystal quality. In this work, we applied a slot-die coating method to deposit a MA-free perovskite thin film with a subsequently introduced FA+ replenishment to induce a second growth and prepare a FA-rich film. As a result, the inverted perovskite mini-module reached an efficiency of 17.56% with an aperture area of 60.84 cm2.

Impermeable Atomic Layer Deposition for Sputtering Buffer Layer in Efficient Semi-Transparent and Tandem Solar Cells via Activating Unreactive Substrate.

Atomic layer deposition (ALD) turns out to be particularly attractive technology for the sputtering buffer layer when preparing the semi-transparent (ST) perovskite solar cells (PSCs) and the tandem solar cells. ALD process turns to be island growth when the substrate is unreactive with the ALD reactants, resulting in the pin-hole layer, which causes an adverse effect on anti-sputtering. Here, p-i-n structured PSCs with ALD SnOx as sputtering buffer layer are conducted. The commonly used electron transportation layer (ETL) PCBM in the p-i-n structured PVK solar cell is an unreactive substrate that prevents the layer-by-layer growth for the ALD SnOx . PCBM layer is activated by introducing reaction sites to form impermeable ALD layers. By introducing reaction sites/ALD SnOx as sputtering buffer layer, the authors succeed to fabricate ST-PSCs and perovskite/silicon (double-side polished) tandem solar cells with power conversion efficiency (PCE) of 20.25% and 23.31%, respectively. Besides, the unencapsulated device with reaction sites maintains more than 99% of the initial PCE after aging over 5100 h. This work opens a promising avenue to prepare impermeable layer for stable PSCs, ST-PSCs, tandem solar cells, and the related scale-up solar cells.

Br Vacancy Defects Healed Perovskite Indoor Photovoltaic Modules with Certified Power Conversion Efficiency Exceeding 36.

Indoor photovoltaics (IPVs) are expected to power the Internet of Things ecosystem, which is attracting ever-increasing attention as part of the rapidly developing distributed communications and electronics technology. The power conversion efficiency of IPVs strongly depends on the match between typical indoor light spectra and the band gap of the light absorbing layer. Therefore, band-gap tunable materials, such as metal-halide perovskites, are specifically promising candidates for approaching the indoor illumination efficiency limit of ∼56%. However, perovskite materials with ideal band gap for indoor application generally contain high bromine (Br) contents, causing inferior open-circuit voltage (VOC ). By fabricating a series of wide-bandgap perovskites (Cs0.17 FA0.83 PbI3- x Brx , 0.6 ≤ x ≤ 1.6) with varying Br contents and related band gaps, it is found that, the high Br vacancy (VBr ) defect density is a significant reason that leading to large VOC deficits apart from the well-accepted halide segregation. The introduction of I-rich alkali metal small-molecule compounds is demonstrated to suppress the VBr and increase the VOC of perovskite IPVs up to 1.05 V under 1000 lux light-emitting diode illumination, one of the highest VOC values reported so far. More importantly, the modules are sent for independent certification and have gained a record efficiency of 36.36%.

Slot-die coating large-area formamidinium-cesium perovskite film for efficient and stable parallel solar module.

Perovskite solar cells have emerged as one of the most promising thin-film photovoltaic (PV) technologies and have made a strong debut in the PV field. However, they still face difficulties with up-scaling to module-level devices and long-term stability issue. Here, we report the use of a room-temperature nonvolatile Lewis base additive, diphenyl sulfoxide(DPSO), in formamidinium-cesium (FACs) perovskite precursor solution to enhance the nucleation barrier and stabilize the wet precursor film for the scalable fabrication of uniform, large-area FACs perovskite films. With a parallel-interconnected module design, the resultant solar module realized a certified quasi-stabilized efficiency of 16.63% with an active area of 20.77 cm2 The encapsulated modules maintained 97 and 95% of their initial efficiencies after 10,000 and 1187 hours under day/night cycling and 1-sun equivalent white-light light-emitting diode array illumination with maximum power point tracking at 50°C, respectively.

Tailoring C60 for Efficient Inorganic CsPbI2 Br Perovskite Solar Cells and Modules.

Although inorganic perovskite solar cells (PSCs) are promising in thermal stability, their large open-circuit voltage (VOC ) deficit and difficulty in large-area preparation still limit their development toward commercialization. The present work tailors C60 via a codoping strategy to construct an efficient electron-transporting layer (ETL), leading to a significant improvement in VOC of the inverted inorganic CsPbI2 Br PSC. Specifically, tris(pentafluorophenyl)borane (TPFPB) is introduced as a dopant to lower the lowest unoccupied molecular orbital (LUMO) level of the C60 layer by forming a Lewis acidic adduct. The enlarged free energy difference provides a favorable enhancement in electron injection and thereby reduces charge recombination. Subsequently, a nonhygroscopic lithium salt (LiClO4 ) is added to increase electron mobility and conductivity of the film, leading to a reduction in the device hysteresis and facilitating the fabrication of a large-area device. Finally, the as-optimized inorganic CsPbI2 Br PSCs gain a champion power conversion efficiency (PCE) of 15.19%, with a stabilized power output (SPO) of 14.21% (0.09 cm2 ). More importantly, this work also demonstrates a record PCE of 14.44% for large-area inorganic CsPbI2 Br PSCs (1.0 cm2 ) and reports the first inorganic perovskite solar module with the excellent efficiency exceeding 12% (10.92 cm2 ) by a self-developed quasi-curved heating method.

Interfacial engineering with carbon-graphite-Cu δ Ni1-δ O for ambient-air stable composite-based hole-conductor-free perovskite solar cells.

Ambient air atmosphere is inimical to organic-inorganic halide perovskites and organic hole transport materials, and is, thus, necessarily avoided during device fabrication. To solve this issue, it is highly desirable to design stable perovskite-based composites and device configurations. Here, fully ambient-air and antisolvent-free-processed, stable and all-inorganic metal-oxide selective contact hole-conductor-free perovskite solar cells (HCF-PSCs) based on perovskite-based composites with an interfacial engineering strategy are reported. The formation of perovskite-based composites by interfacial engineering with carbon-graphite-Cu δ Ni1-δ O not only improved interfacial contacts, charge extraction and transport but also passivated trap states of perovskite thin films and charge recombination at the interfaces. Thus, such perovskite composites with interfacial engineering-based HCF-PSCs without encapsulation showed excellent stability by sustaining 94% of initial PCE over 300 days under ambient conditions.

Hybrid Inorganic Electron-Transporting Layer Coupled with a Halogen-Resistant Electrode in CsPbI2Br-Based Perovskite Solar Cells to Achieve Robust Long-Term Stability.

Along with the rapidly developed power conversion efficiencies (PCEs), operational stability of perovskite solar cells (PSCs) remains a bottleneck for further commercialization. The instability mainly arises from the unstable organic components in the whole devices and the responsive metal electrode to the halogens from perovskites. In this work, we develop a carbide-titanium oxide (C-TiO2) hybrid electron-transporting layer (ETL) and a halogen-resistant Sb electrode on top of the inorganic CsPbI2Br layer to solve the issues of instability. The hybrid C-TiO2 presents a uniform and pinhole-free morphology, adequate band structure and electronic property, and observably strong stability. On the other hand, Sb is demonstrated to be effective to restrict inferior ion diffusion and further perovskite decomposition. As a result, our well-designed PSCs achieve both high efficiencies (14.8% for the champion device) and long-term stabilities (<6% decline @ 85 °C, dark, <10% decline @ 60 °C, continuous illumination) of 1000 h.

Efficient Methylamine-Containing Antisolvent Strategy to Fabricate High-Efficiency and Stable FA0.85Cs0.15Pb(Br0.15I2.85) Perovskite Solar Cells.

Antisolvent and additive strategies are significantly positive to improve the crystal quality, device performance, and long-term stability of perovskite solar cells (PSCs). In addition, the high-quality perovskite thin films could be prepared by the methylamine (MA) gas-induced defect-healing process. However, until now, the research on adding MA into the antisolvent, which may take the advantages of two efficiently modified strategies, is still not systematically studied. Here, we add the MA additive into the chlorobenzene antisolvent to fabricate the FA0.85Cs0.15Pb(Br0.15I2.85) films and achieve the high-quality light-absorbing layers with the preferred orientation of (101). The use of an antisolvent, with an appropriate amount of MA in chlorobenzene, leads to extremely uniform and dense perovskite layers with a better hydrophobic performance and enables the fabrication of remarkably improved solar cells with a power conversion efficiency (PCE) of 19.6% for a champion cell. This strategy shows an encouraging improvement of more than 13.95% compared with the traditional antisolvent strategy. The high-efficiency devices could maintain more than 95 or 88% of their initial PCEs after 500 h under continuous light soaking or thermal aging in the dark at 85 °C in a N2-filled glove box, respectively. These results provide an important progress in the realization of highly efficient and stable PSCs.

Controlling Orientation Diversity of Mixed Ion Perovskites: Reduced Crystal Microstrain and Improved Structural Stability.

Formamidinium lead iodide (FAPbI3)-based perovskite has attracted increasing attention of researchers due to its lower band gap and improved thermal stability. However, it is structurally unstable and easy to phase-transfer at room temperature. Here, we improve the structural stability of perovskite by controlling its orientation diversity. XRD results show that incorporating CsBr into FAPbI3 is effective to adjust the crystal plane stacking. For the first time, an orientation diversity factor (ODF) is identified, and it is found that an increased ODF is propitious to decrease the lattice distortion and relax the microstrain in the crystal, boosting the efficiency and stability of the perovskite solar cells (PSCs). The optimized inverted PSC based on FA0.85Cs0.15PbI2.85Br0.15 achieves efficiency of 17.59% and presents ignored performance decline under continuous light-soaking for 500 h.

A chemically inert bismuth interlayer enhances long-term stability of inverted perovskite solar cells.

Long-term stability remains a key issue impeding the commercialization of halide perovskite solar cells (HPVKSCs). The diffusion of molecules and ions causes irreversible degradation to photovoltaic device performance. Here, we demonstrate a facile strategy for producing highly stable HPVKSCs by using a thin but compact semimetal Bismuth interlayer. The Bismuth film acts as a robust permeation barrier that both insulates the perovskite from intrusion by undesirable external moisture and protects the metal electrode from iodine corrosion. The Bismuth-interlayer-based devices exhibit greatly improved stability when subjected to humidity, thermal and light stresses. The unencapsulated device retains 88% of its initial efficiency in ambient air in the dark for over 6000 h; the devices maintain 95% and 97% of their initial efficiencies after 85 °C thermal aging and light soaking in nitrogen atmosphere for 500 h, respectively. These sound stability parameters are among the best for planar structured HPVKSCs reported to date.

[6,6]-Phenyl-C61-Butyric Acid Methyl Ester/Cerium Oxide Bilayer Structure as Efficient and Stable Electron Transport Layer for Inverted Perovskite Solar Cells.

Stability issues and high material cost constitute the biggest obstacles of a perovskite solar cell (PVSC), hampering its sustainable development. Herein, we demonstrate that, after suitable surface modification, the low-cost cerium oxide (CeO x) nanocrystals can be well dispersed in both polar and nonpolar solvents and easily processed into high-quality electron transport layers (ETLs). The inverted PVSC with the configuration of "NiMgLiO/MAPbI3/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/CeO x" has achieved a high efficiency up to 18.7%. Especially, the corresponding devices without encapsulation can almost keep their initial PCEs in 30% humidity-controlled air in the dark for 30 days and also show no sign of degradation after continuous light soaking and maximum power point tracking for 200 h in a N2 atmosphere. These results have been proved to be associated with the dual functions achieved by the PCBM/CeO x bilayer ETLs in both efficient electron extraction and good chemical shielding. Furthermore, an all inorganic interfacial layer based PVSC with the configuration of "NiMgLiO/MAPbI3/CeO x" has also achieved a promising efficiency of 16.7%, reflecting the potential to fabricate efficient PVSCs with extremely low cost.

Pr and F co-doped SnO2 transparent conductive films with high work function deposited by ion-assisted electron beam evaporation.

A transparent conductive oxide (TCO) Pr and F co-doped SnO2 (PFTO) film is prepared by ion-assisted electron beam deposition. An optimized PFTO film shows a high average visible optical transmittance of 83.6% and a minimum electrical resistivity of 3.7 × 10(-3) Ω·cm corresponding to a carrier density of 1.298 × 10(20) cm(-3) and Hall mobility of 12.99 cm(2)/V⋅s. This PFTO film shows a high work function of 5.147 eV and favorable surface morphology with an average roughness of 1.45 nm. Praseodymium fluoride is found to be an effective material to dope F into SnO2 that can simplify the fabrication process of SnO2-based TCO films.