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Abstract Atmospheric thermal assisted blade coating (TABC) method, which is quick film crystallization and easier fabrication than the commonly used spin-coating process, to prepare a high quality CH3NH3PbI3 perovskite film is investigated in this work. Selection of the perovskite precursor solvents and controlling the ratio of the mixed solvent as well as substrate temperature for perovskite film formation are important factors in this TABC process. Based on the results obtained in this work, substrate temperature is the key factor for managing the perovskite film phase transition which influences the film roughness and crystallinity. Furthermore, the high-quality perovskite films are prepared by perovskite precursors with mixture of solvents containing GBL/DMSO at the ratio from 1/9 to 5/5. By using the optimum substrate temperature of 130 °C and the GBL/DMSO solvent ratio of 1/9 (G01D09) for the preparation of small area n-i-p and p-i-n PSCs as well as the p-i-n type perovskite sub-module, the power conversion efficiencies of 17.55%, 16.90% and 13.03%, respectively, are acquired under the illumination of 100 mW/cm2 (AM 1.5G).

Abstract An earth-abundant and relatively less toxic, quaternary Cu2ZnSnSe4 (CZTSe) quantum dots (QDs) were prepared by hot injection method at low temperature to use as a sensitizer for QDSC. The formation of tetragonal phase and stoichiometry were confirmed by X-ray diffraction (XRD), Raman spectroscopy and energy dispersive X-ray (EDX) analysis, respectively. The UV–Vis-NIR and photoluminescence spectroscopy was used to determine the bandgap (1.66 eV) and narrow emission (1050–1130 nm) range. Moreover, transmission electron microscopy (TEM) was used to find out the average size of CZTSe QDs and it was found to be ∼5 nm. It can highly adsorb on the porous TiO2 nanofibers (NFs) and enhance the absorbance due to its smaller size. The photoconversion efficiency was investigated using the prepared CZTSe QDs sensitized porous TiO2 NFs based QDSC and its photoconversion efficiency (PCE) was found to be 3.61% which is higher than that of the conventional TiO2 NFs based QDSC (η ≈ 2.84%).

Abstract The present work deals with the green solar assisted synthesis of chalcone (3-(4-fluorophenyl)-1-(4-methoxyphenyl)-prop-2-en-1-one). To check the efficacy of the process, chalcone has been synthesized by photochemical (UV radiation), thermal method (60 °C) and the conventional method. The effect of catalyst concentration and temperature on the yield of the product has been studied. The synthesized chalcone derivative was characterised using Fourier Transform Infrared (FTIR) Spectroscopy, Liquid chromatography–mass spectrometry (LCMS) elemental analysis, X-ray diffraction analysis (XRD) and thermal analysis (TG/DTA). The time required for the completion of the reaction using solar assisted method and conventional method were 10 min and 240 min (4 h), respectively. The crystallinity of material produced using concentrated solar radiation (CSR) was 14.16% higher than the conventional method. The amount of energy required to produce chalcone using CSR is 90.37% less energy than the conventional method. CSR was found to be green, simple and energy efficient novel idea for the synthesis of chalcone.

Abstract In building integrated photovoltaic (BIPV) systems, PV elements are integrated along with the building which often serves as the exterior weathering skin. PV researchers from various countries have been working for several years to optimize these systems. Sustainable BIPV system has many benefits such as the building itself becomes the PV support structure, and the BIPV components displace the conventional building materials and labor cost, thereby reducing the net installed cost of the PV system and building construction. It also provides on-site generation of electricity and architectural elegance, which increases the market acceptance of the buildings. The BIPV systems can be interfaced with the available utility grid or used as off-grid systems. This paper identifies sustainable building concept in South Asian countries and role of BIPV applications in sustainable building. This article gives review of BIPV applications in South Asian countries. Finally, Barrier and challenges of BIPV system have been discussed and future direction is highlighted.

Abstract Energy rating of PV module as per the site-specific climatic condition is essential for customer’s point of view to choose suitable PV technologies. For site and technology-specific energy rating of PV module, it is essential to design standard datasets for it. In this paper, energy ratings of three different technologies with the data sets based on the angle of incidence, spectrum, irradiance, wind and temperature using existing formulae has been reported. The performance surfaces of PV technologies are designed based on the IEC 61853-1 & 2, and IEC 60891. A procedure is reported to including the degradation rate in the energy rating method. Comparisons of energy rating of amorphous silicon, HIT and multi-crystalline silicon using the existing method considering the degradation rate are done with the measured data. It has been observed that all the three technologies at Cold & sunny zone shows the highest energy rating. A procedure, to find out the most frequent conditions in terms of occurrence probability for different PV technologies is also reported.

Abstract Recently a simple explicit model was introduced to represent the J–V characteristics of an illuminated solar cell with parasitic resistances and bias dependent photocurrent as j = (1 − vm)/(1 + αv), here the normalized voltage, v and normalized current density j can be represented as v = V/Voc and j = J/Jsc respectively, where Voc is the open circuit voltage and Jsc is the short circuit current density. The model is an equivalent rational function form and useful for design, characterization and calculation of maximum power point voltage. The model is intuitive and lacks the analytical support. In this paper an analytical derivation of the model is presented using the physics based implicit J–V equation.

Abstract Quantum efficiency and impedance spectroscopy tools are employed for understanding the influence of parasitic absorption losses and partial field effect surface passivation by the silver nanoparticles (Ag NPs) on electrical properties of textured silicon solar cells without and with Si3N4 spacer layer. The parasitic absorption losses from Ag NPs reduced the internal quantum efficiency near the surface plasmon resonance region. The passive components like; series and parallel resistances, chemical capacitance of solar cells without and with Ag NPs are estimated after fitting impedance semicircles, which are further used for estimating effective carrier lifetime (τeff) values. Under AM1.5G illumination, cells with Si3N4 spacer layer showed a large decrease in the τeff due to the strong parasitic absorption losses from the Ag NPs. But, the cells without Si3N4 spacer layer showed a small decrease in the τeff due to the reduced surface recombination after partial field effect passivation from near-fields of Ag NPs’ surface plasmon resonances on the emitter surface.

Abstract Thermal annealing is an important process to improve the power conversion efficiency (PCE) of bulk-hetero junction organic solar cells (BHJ OSCs) by inducing micro-structural changes within the active layer blend’s constituents leading to amelioration of charge transfer/transport dynamics and interfacial properties. This work investigates the impact of thermal annealing on the photovoltaic performance ofPoly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7):[6,6]-Phenyl C71-butyric acid methyl ester (PC71BM) (PTB7:PC71BM) thin film blend in the presence of DIO (1,8 –Diiodooctane) additive, at different annealing temperatures (40, 60 and 80 °C) and correlates with the performance of DIO-free devices investigated under similar annealing conditions. Our results show that DIO-containing (w/DIO)blends, annealed at moderate temperature (40 °C) for 1 h exhibit significantly improved short circuit current (Jsc)as well as fill factor (FF) and hence 25% improvement in PCE over bench dried (unannealed) DIO-containing blend films. Interestingly, thermal treatment of DIO containing blend films at a higher temperature of 80 °C results in significant reduction of FF. However, for without DIO (w/o DIO) devices, FF remains unchanged while decrease in Jsc is significant. The inferior performance of both (w/DIO and w/o DIO) the devices at higher temperatures ~80 °C emanates from an unfavorable distribution of the polymer- fullerene network, as shown by morphological and surface potential analyses. Specifically, in w/DIO devices, the decreased performance is possibly induced by the temperature driven, accelerated loss of DIO additive that produces the evolution of undesirable morphology thus deteriorating the performance.

Abstract This paper reports an experimental study on the performance characteristics of four solar air heaters. Two were of a corrugated type and two were of a mesh type. All used ordinary black-painted surfaces. Instead of comparing the efficiencies at the same rate of discharge, the same amount of pumping power was employed so that the unequal frictional losses were also taken into account in the comparison of over-all heater efficiency. The rating parameters, such as plate efficiency factor, heat-removal efficiency factor, over-all heat-loss coefficient, and the effective absorption coefficient have been reported for average winter conditions for these heaters at Roorkee, India. The air-heater performance can be computed from these parameters for any other usual range of operating conditions.