Estimation of spectral mismatch correction factor f1' indicated by radiometer responsivity toward phototherapic infant devices.

The main aim of this research is to assess the variation in phototherapy radiometer responsivities toward the optical power of the phototherapeutic devices and hence estimate the spectral mismatch correction factor f1'. Two conventional phototherapy devices were studied to verify their spectral irradiance and three different phototherapy radiometers were studied for their responsivity at the range 400-500 nm. The results show the dependence of total irradiance measurement of phototherapy sources on matching between phototherapy radiometer band responsivity and spectral irradiance of the phototherapy sources. The spectral mismatch values vary from 13% to 47% of the total measured irradiance for the three radiometers. These mismatch values could be added to the measured irradiance as a correction.

Synthesis and numerical simulation of formamidinium-based perovskite solar cells: a predictable device performance at NIS-Egypt.

Formamidinium lead triiodide (δ-FAPbI3)-based perovskite solar cells showed remarkable potential as light harvesters for thin-film photovoltaics. Herein, the mechanochemical synthesis of δ-FAPbI3, MAPbI3, and mixed-cation FA1-xMAxPbI3 with (x = 0.3, 0.5, and 0.7) perovskite materials were prepared as a novel green chemistry method for scaling up production. Crystallinity, phase identification, thermal stability, optoelectronic properties, and nanoscale composition are discussed. The results demonstrated that the prepared mixed-cation samples are enhanced in the visible absorption region and are consistent with previous works. The crystal structure of δ-FAPbI3 was altered to a cubic structure due to the change in FA-cation. Moreover, the performance of [Formula: see text]-FA-based perovskites was investigated using the Solar Cell Capacitance Simulator (SCAPS-1D) software. The validity of the device simulation was confirmed by comparing it to real-world devices. The photovoltaic characteristics and impact of absorber thickness on device performance were explained. The [Formula: see text]-FA-based solar cell with a 50% MA-doped molar ratio shows a better performance with an efficiency of 26.22% compared to 8.43% for δ-FAPbI3. The outcome results of this work confirm the beneficial effect of mixed cations on device operation and advance our knowledge of the numerical optimization of perovskite-based solar cells.