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Abstract An experimental investigation has been carried out to study flow and heat transfer in solar air heater for inline holes inserted between absorber and back plate. The analysis has been carried out for cross flow conditions. The effect of flow and geometrical parameters, especially jet diameter and hydraulic diameter has been studied. Mass flow rate for the study is varied corresponding to the Reynolds number range of 4600–12,000. The jet diameter, streamwise pitch, and spanwise pitch, each normalized by hydraulic diameter, i.e. Dj/Dh, X/Dh, and Y/Dh, are in the range: 0.053–0.084, 0.53–0.63, and 0.53–0.63 respectively. Performance is studied in terms of Temperature Rise Parameter (TRP), collector efficiency, and Nusselt number. Hourly variations of solar intensity have also been shown. Collector efficiency increases and Temperature Rise Parameter decreases with increase in mass flow rate for all geometrical configurations. All the above-listed performance parameters are found to be maximum at jet diameter to hydraulic diameter ratio of 0.07. A correlation for Nusselt number in terms of Reynolds number, jet diameter, and hydraulic diameter has also been developed.

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).

It has been found that the values of ratio of hourly global illuminance to daily global illuminance, rvt, are very close to the corresponding values for global solar radiation, rt, examined from the measured data of six IDMP [1] (International Day light Measurement Programme) locations. This has been further confirmed by examining the values for rvt and rt as calculated from TMY2 [2] (Typical Metrological Year) data base for primary locations. Based on this, it has been proposed that the correlations available in literature to predict rt can be employed to predict rvt. Adequacy of the correlation due to Collares-Pereira and Rabl [3] available for rt has been examined to predict rvt as obtained from TMY2 data base for the 56 primary locations. It has been found that the values of rvt obtained from measured illuminance data of six locations have been predicted within a rms difference of 2.71% and within a rms difference of 4.3% for the 56 primary locations of TMY2 data when the correlation due to Collares-Pereira and Rabl for rt has been employed.

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%).

CdSxSe1−x films of different composition (0 < x < 1) were deposited by pulse plating technique at different duty cycles in the range of 10–50%. The films were polycrystalline and exhibited hexagonal structure. The band gap of the films varies from 1.68 to 2.39 eV as the concentration of CdS increases. Energy Dispersive analysis of X-rays (EDAX) measurements indicate that the composition of the films are nearly the same as that of the precursors considered for the deposition. Atomic force microscopy studies indicated that the grain size increased from 20 to 200 nm as the concentration of CdSe increased. Photoelectrochemical (PEC) cell studies indicated that the films of composition CdS0.9Se0.1 exhibited maximum photoactivity. Mott-Schottky studies indicated that the films exhibit n-type behaviour. Spectral response measurements indicated that the photocurrent maxima occurred at the wavelength value corresponding to the band gap of the films.