Lead halide perovskites are the new rising generation of semiconductor materials due to their unique optical and electrical properties. The investigation of the interaction of halide perovskites and light is a key issue not only for understanding their photophysics but also for practical applications. Hence, tremendous efforts have been devoted to this topic and brunch into two: (i) decomposition of the halide perovskites thin films under light illumination; and (ii) influence of light soaking on their photoluminescence (PL) properties. In this review, we for the first time thoroughly compare the illumination conditions and the sample environment to correlate the PL changes and decomposition of perovskite under light illumination. In the case of vacuum and dry nitrogen, PL of the halide perovskite (MAPbI_3–xCl_x, MAPbBr_3–xCl_x, MAPbI₃) thin films decreases due to the defects induced by light illumination, and under high excitations, the thin film even decomposes. In the presence of oxygen or moisture, light induces the PL enhancement of halide perovskite (MAPbI₃) thin films at low light illumination, while increasing the excitation, which causes the PL to quench and perovskite thin film to decompose. In the case of mixed halide perovskite ((MA)Pb(Br_xI_1-x)₃) light induces reversible segregation of Br domains and I domains. 

Electricity generation around the world is mainly produced by using non-renewable energy sources especially in the commercial buildings. However, Rooftop solar Photovoltaic (PV) system produced a significant impact on environmental and economical benefits in comparison to the conventional energy sources, thus contributing to sustainable development. Such PV’s system encourages the production of electricity without greenhouse gas emissions that leads to a clean alternative to fossil fuels and economic prosperity even in less developed areas. However, efficiency of rooftop solar PV systems depends on many factors, the dominant being geographical (latitude, longitude, and solar intensity), environmental (temperature, wind, humidity, pollution, dust, rain, etc.) and the type of PV (from raw material extraction and procurement, to manufacturing, disposal, and/or recycling) used. During the feasibility analysis of the environment, geographical conditions are keep in well consideration, but the pollution level of the city is always overlooked, which significantly influences the performance of the PV installations.     

Therefore, this research work focused on the performance of rooftop solar PV installed in one of the most polluted city in India. Here, the loss in power generation of rooftop solar PV has been studied for the effect of deposited dust particles, wind velocity before and after the cleaning of the panels. The actual data has been utilized for the calculation of the energy efficiency and power output of the PV systems. According to the results, it has been concluded that dust deposition, wind speed and pollution level in city significantly reduces the efficiency of solar photovoltaic panel. Hence, an overview of social and environmental impacts of PV technologies is presented in this paper along with potential benefits and pitfalls.

With the continuous development of facilities and horticulture, the area of vegetable planting in facilities increased year by year. Watermelon (Citrullus vulgaris Schrad) as the main cultivars within the facility, the continuous cropping problem is very serious, resulting in continuous cropping obstacles become increasingly obvious, the incidence of fusarium wilt increased year by year. Grafted watermelon roots developed to improve the growth of grafted roots of the conditions, resulting in robust plant growth. At the same time, the use of different purposes of the rootstock can make watermelon in different soil conditions under normal growth, such as the use of low temperature, drought, salt tolerance, barren and other characteristics of the rootstock. Secondly, the rootstock of the strong absorption of water absorption capacity, to promote the growth of grafted watermelon plants strong, large watermelon fruit, high yields. In addition, grafted watermelon seedlings grow fast early, for early maturing cultivation and overcome the seedless watermelon early growth slow defects is extremely favorable. So the use of pumpkin as a watermelon grafting rootstock, can effectively improve the effect of watermelon resistance to Fusarium wilts. And provide the theoretical basis and scientific basis for the further study of photosynthetic characteristics, disease resistance breeding and effective control of watermelon. In this experiment, the watermelon varieties with different resistance to fusarium wilt were selected, and the anti-fusarium wilt watermelon was studied systematically. There are changes in physiological characteristics during growth and development. In conclusion, grafting promotes the growth of watermelon and physiological characteristics of the index rose.

KEYWORDS: watermelon; fusarium wilt; growth period; physiological characteristics

Hospital waste containing antibiotics is toxic to the ecosystem. Ciprofloxacin is one of the essential, widely used antibiotics and is often detected in water bodies and soil. It is vital to treat these medical wastes, which urge new research towards waste management practices in hospital environments themselves. Ultimately minimizes its impact in the ecosystem and prevents the spread of antibiotic resistance. The present study highlights the decomposition of ciprofloxacin using nano-catalytic ZnO materials by reactive oxygen species (ROS) process. The most effective process to treat the residual antibiotics by the photocatalytic degradation mechanism is explored in this paper. The traditional co-precipitation method was used to prepare zinc oxide nanomaterials. The characterization methods, X-Ray diffraction analysis (XRD), Fourier Transform infrared spectroscopy (FTIR), Ulraviolet-Visible spectroscopy (UV-Vis), Scanning Electron microscopy (SEM) and X-Ray photoelectron spectroscopy (XPS) have done to improve the photocatalytic activity of ZnO materials. The mitigation of ciprofloxacin catalyzed by ZnO nano-photocatalyst was described by pseudo-first-order kinetics and chemical oxygen demand (COD) analysis. In addition, ZnO materials help to prevent bacterial species, S. aureus and E. coli, growth in the environment. This work provides some new insights towards ciprofloxacin degradation in efficient ways.

In this paper, we modeled and simulated two tandem solar cell structures (a) and (b), in a two-terminal configuration based on inorganic and lead-free absorber materials. The structures are composed of sub-cells already studied in our previous work, where we simulated the impact of defect density and recombination rate at the interfaces, as well as that of the thicknesses of the charge transport and absorber layers, on the photovoltaic performance. We also studied the performance resulting from the use of different materials for the electron and hole transport layers. The two structures studied include a bottom cell based on the perovskite material CsSnI₃ with a band gap energy of 1.3 eV and a thickness of 1.5 µm. The first structure has an upper sub-cell based on the CsSnGeI₃ material with an energy of 1.5 eV, while the second has an upper sub-cell made of Cs₂TiBr₆ with a band gap energy of 1.6 eV. The theoretical model used to evaluate the photocurrent density, current-voltage characteristic, and photovoltaic parameters of the constituent sub-cells and the tandem device was described. Current matching analysis was performed to find the ideal combination of absorber thicknesses that allows the same current density to be shared. An efficiency of 29.8% was obtained with a short circuit current density J_sc = 19.92 mA/cm², an open circuit potential V_oc = 1.46 V and a form factor FF = 91.5% with the first structure (a), for a top absorber thickness of CsSnGeI₃ of 190 nm, while an efficiency of 26.8% with J_sc = 16.74, V_oc = 1.50 V and FF = 91.4% was obtained with the second structure (b), for a top absorber thickness of Cs₂TiBr₆ of 300 nm. The objective of this study is to develop efficient, low-cost, stable and non-toxic tandem devices based on lead-free and inorganic perovskite.

In the past three decades, nanotechnology has attracted extensive attention. People have many expectations on the utilization of nanotechnology in medicine, but unfortunately, these expectations are unlikely to be realized. In the field of nanotechnology, the niche for building commercial products has not been developed yet. However, metal nanoparticles have attracted people’s attention since ancient times because of their optical properties, which are very different from those of bulk metals. By understanding the origin of these optical properties and using current technology, these nanoparticles can be manipulated to build a palette. Using micro measurement equipment, the palette can be printed with very good resolution.