Comparison of theoretical and experimental results for band-gap-graded CZTSSe solar cell

The simulation of CZTSSe solar cells is presented in this paper. The simulation results are in reasonable agreement with the experimental data, indicating the reliability of simulation results. New structure is proposed to increase the functionality of the cell. Improved functional performances are achieved by inserting a P-Silicon (P-Si) layer as back surface field. Simulation results suggest that by inserting this P-Si layer, efficiency of the CZTSSe solar cell increases from 12.6% to 16.59%, which is a significant improvement. For the champion cell JSC = 36.27 mA/cm2, VOC = 0.625 V and FF = 73.11% has been achieved. © 2017 Elsevier B.V.1

Optimization of power used in liver cancer microwave therapy by injection of Magnetic Nanoparticles (MNPs)

In this paper, the effects of the input power of a microwave antenna (MWAN) on liver cancer tissue when injected with Magnetic Nanoparticles (MNPs) are studied. First, for basic simulation, we validated our results by comparison with other literature data. After that, we used a 1.8-cm hepatocellular carcinoma (HCC) tumor, which was treated experimentally for 3-min ablation using MWAN operating at a frequency of 2.45 GHz with a power of 90 W. At the next step of the simulation, the obtained results were compared with experimental results. As a last step, the effects of various MWAN input powers on the tumor after injection of MNPs were studied. Our results show that MNPs can be used as excellent heat sources and reduce input power significantly to produce a similar hyperthermia. When maghemite γ-Fe2O3 MNPs are used, the input power decreases from 90 W to 35 W. In addition, it has been shown that using a higher external magnetic field can treat a larger tumor. The optimized simulated values of the external magnetic field and the input microwave power are 15 mT and 35 W, respectively

Improve the performance of CZTSSe solar cells by applying a SnS BSF layer

In this study, the CZTSSe (Cu2ZnSn(S,Se)4) solar cells, with Al/ZnO:Al/ZnO (i)/CdS/CZTSSe/Mo structure, have been simulated. The simulation results have been compared and validated with real experimental results. Next, suggestions for improving the performance of CZTSSe solar cell have been provided. A SnS layer has been used as back surface field (BSF) layer. Different physical parameters of SnS layer are investigated, and the optimum values are selected. It has been found that by inserting a BSF layer with optimum parameters, the efficiency of CZTSSe solar cell increases from 12.3% to 17.25% due to enhancement of both short-circuit current density (Jsc) and open circuit voltage (Voc). For this optimized cell structure, the maximum Jsc = ~37.37 mA/cm2, Voc = ~0.605 V, and fill factor = 76.28% are obtained under 1.5 AM illumination. © 2017 Elsevier Ltd.1

A modeling study on utilizing SnS2 as the buffer layer of CZT(S, Se) solar cells

CdS is conventionally used as the n-type buffer layer in chalcopyrite (CIG(S, Se)) and Kesterite (CZT(S, Se)) solar cells. CdS is toxic and there are wide attempts to find substitutes for it. Here, we suggest SnS2 as a possible alternative. SnS2 films were deposited by pulsed laser deposition (PLD), characterized to estimate carrier concentration and electron affinity values, and the obtained values were used to model a CZT(S, Se) solar cell. The experimental values of a benchmark CZT(S, Se) cell with efficiency of 12.3% were employed to obtain the density and energy position of defects in CZT(S, Se) and validating the model. We observed that SnS2 results in almost identical performance as CdS, showing slightly better current density, due to smaller conduction band offset of 0.21 eV compared to 0.28 eV for CdS. © 2018 Elsevier Ltd1