Perovskites are a category of materials with a unique crystal structure that allows them to absorb sunlight efficiently. This efficiency is particularly high in the case of CH<sub>3</sub>NH<sub>3<...Perovskites are a category of materials with a unique crystal structure that allows them to absorb sunlight efficiently. This efficiency is particularly high in the case of CH<sub>3</sub>NH<sub>3</sub>Pb<sub>1-x</sub>Sn<sub>x</sub>I<sub>3</sub> mixed perovskites. The combination of lead (Pb) and tin (Sn) in this matrix provides a broad spectrum of sunlight absorption, enabling the generation of a larger voltage and, subsequently, increased power. The primary objective in solar cell development is to maximize the conversion of sunlight into electricity. Mixed perovskites like CH<sub>3</sub>NH<sub>3</sub>Pb<sub>1-x</sub>Sn<sub>x</sub>I<sub>3</sub> have demonstrated significant potential in this regard. Their tunable bandgap, courtesy of varying the Pb: Sn ratio, allows for the optimization of sunlight absorption. The result is solar cells that surpass many conventional counterparts in terms of energy efficiency. Another significant advantage of these mixed perovskite solar cells is their cost-effectiveness. They can be manufactured using solution-based processes, which are less expensive than the high-vacuum methods required for traditional silicon solar cells. While the prospects for mixed perovskite solar cells are undeniably promising, there are concerns about the toxicity of lead, a key component of these cells. Lead is known to have harmful effects on the environment and health. The aim of our work is to reduce or eliminate lead toxicity in the perovskite cell while maintaining its efficiency. Thus, in a theoretical and experimental approach, we obtained following efficiencies of samples: CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (22.49%) CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.75</sub>Sn<sub>0.25</sub>I<sub>3</sub> (22.72%), CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.5</sub>Sn<sub>0.5</sub>I<sub>3</sub> (23.00%) CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.25</sub>Sn<sub>0.75</sub>I<sub>3</sub> (22.61%), CH<sub>3</sub>NH<sub>3</sub>SnI<sub>3</sub> (22.38%). Doping with 50% tin gives the highest result (23.00%). By replacing a fraction of the lead with tin, the research aims to reduce the environmental footprint of the cells while maintaining their high performance. However, the challenge is to achieve a balance that does not compromise performance while reducing toxicity. .展开更多
Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks ...Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath （HybPL） algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection （MRU-DP） algorithm which offers better performance than the Dedicated Protection （DP） algorithm.展开更多
In recent years, there has been an unprecedented rise in the performance of metal halide perovskite solar cells. The lead-free perovskite solar cells (PSCs) have drawn much research interest due to the Pb toxicity of ...In recent years, there has been an unprecedented rise in the performance of metal halide perovskite solar cells. The lead-free perovskite solar cells (PSCs) have drawn much research interest due to the Pb toxicity of the lead halide perovskite. CH3NH3SnI3 is a viable alternative to CH3NH3PbX3. In this work,?we designed a tin-based perovskite simulated model with the novel architecture of (TCO)/buffer (TiO2)/absorber (Perovskite)/hole transport material (HTM) and analyzed using the solar cell capacitance simulator (SCAPS-1D), which is well adapted to study the photovoltaic architectures. In the paper, we studied the influences of perovskite thickness and the doping concentration on the solar cell performance through theoretical analysis and device simulation. The results are indicating that the lead-free CH3NH3SnI3 is having the greatpotential to be an absorber layer with suitable inorganic hole transport materials?like CuI (PCE: 23.25%), Cu2O (PCE: 19.17%), organic hole transport materials?like spiro-OMETAD (PCE: 23.76%) and PTAA (PCE: 23.74%) to achieve high?efficiency. This simulation model will become a good guide for the fabrication?of high efficiency tin-based perovskite solar. The results show that the lead-free CH3NH3SnI3 is a potential environmentally friendly solar cells with high efficiency.展开更多
Numerical simulation has been used to investigate the effect of different buffer?layer components on the performance of CuInGaSe2?solar cells?with SCAPS-1D?software. The main photovoltaic parameters of simulated devic...Numerical simulation has been used to investigate the effect of different buffer?layer components on the performance of CuInGaSe2?solar cells?with SCAPS-1D?software. The main photovoltaic parameters of simulated devices: open-circuit?voltage (Voc), short-circuit current (Jsc), fill factor (FF), and conversion efficiency (h),?areanalysed as a function of thickness and temperature in the different buffer layers used. According to numerical simulation the highest conversion?efficiency (23%) of CIGS solar cell is reached for the CdS buffer layer. This?result is validated by experimental results?(20%). At 300 K, when the thickness?of?the buffer layer (CdS, ZnS, ZnSe,?InSe2) increases from 100 nm to 500?nm,?with the other parameters maintained constant, the efficiency decreases. When the temperature increases from 300 K to 400 K,?with the other parameters maintained?constant, both open circuit voltage and conversion efficiency also decrease.?The?effect of dual buffer layers of ZnS/CdS has also been analysed and his efficiency increases?of 3% than a single buffer CdS.展开更多
文摘Perovskites are a category of materials with a unique crystal structure that allows them to absorb sunlight efficiently. This efficiency is particularly high in the case of CH<sub>3</sub>NH<sub>3</sub>Pb<sub>1-x</sub>Sn<sub>x</sub>I<sub>3</sub> mixed perovskites. The combination of lead (Pb) and tin (Sn) in this matrix provides a broad spectrum of sunlight absorption, enabling the generation of a larger voltage and, subsequently, increased power. The primary objective in solar cell development is to maximize the conversion of sunlight into electricity. Mixed perovskites like CH<sub>3</sub>NH<sub>3</sub>Pb<sub>1-x</sub>Sn<sub>x</sub>I<sub>3</sub> have demonstrated significant potential in this regard. Their tunable bandgap, courtesy of varying the Pb: Sn ratio, allows for the optimization of sunlight absorption. The result is solar cells that surpass many conventional counterparts in terms of energy efficiency. Another significant advantage of these mixed perovskite solar cells is their cost-effectiveness. They can be manufactured using solution-based processes, which are less expensive than the high-vacuum methods required for traditional silicon solar cells. While the prospects for mixed perovskite solar cells are undeniably promising, there are concerns about the toxicity of lead, a key component of these cells. Lead is known to have harmful effects on the environment and health. The aim of our work is to reduce or eliminate lead toxicity in the perovskite cell while maintaining its efficiency. Thus, in a theoretical and experimental approach, we obtained following efficiencies of samples: CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> (22.49%) CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.75</sub>Sn<sub>0.25</sub>I<sub>3</sub> (22.72%), CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.5</sub>Sn<sub>0.5</sub>I<sub>3</sub> (23.00%) CH<sub>3</sub>NH<sub>3</sub>Pb<sub>0.25</sub>Sn<sub>0.75</sub>I<sub>3</sub> (22.61%), CH<sub>3</sub>NH<sub>3</sub>SnI<sub>3</sub> (22.38%). Doping with 50% tin gives the highest result (23.00%). By replacing a fraction of the lead with tin, the research aims to reduce the environmental footprint of the cells while maintaining their high performance. However, the challenge is to achieve a balance that does not compromise performance while reducing toxicity. .
文摘Fast recovery and minimum utilization of resources are the two main criteria for determining the protection scheme quality. We address the problem of providing a hybrid protection approach on elastic optical networks under contiguity and continuity of available spectrum constraints. Two main hypotheses are used in this paper for backup paths computation. In the first case, it is assumed that backup paths resources are dedicated. In the second case, the assumption is that backup paths resources are available shared resources. The objective of the study is to minimize spectrum utilization to reduce blocking probability on a network. For this purpose, an efficient survivable Hybrid Protection Lightpath （HybPL） algorithm is proposed for providing shared or dedicated backup path protection based on the efficient energy calculation and resource availability. Traditional First-Fit and Best-Fit schemes are employed to search and assign the available spectrum resources. The simulation results show that HybPL presents better performance in terms of blocking probability, compared with the Minimum Resources Utilization Dedicated Protection （MRU-DP） algorithm which offers better performance than the Dedicated Protection （DP） algorithm.
文摘In recent years, there has been an unprecedented rise in the performance of metal halide perovskite solar cells. The lead-free perovskite solar cells (PSCs) have drawn much research interest due to the Pb toxicity of the lead halide perovskite. CH3NH3SnI3 is a viable alternative to CH3NH3PbX3. In this work,?we designed a tin-based perovskite simulated model with the novel architecture of (TCO)/buffer (TiO2)/absorber (Perovskite)/hole transport material (HTM) and analyzed using the solar cell capacitance simulator (SCAPS-1D), which is well adapted to study the photovoltaic architectures. In the paper, we studied the influences of perovskite thickness and the doping concentration on the solar cell performance through theoretical analysis and device simulation. The results are indicating that the lead-free CH3NH3SnI3 is having the greatpotential to be an absorber layer with suitable inorganic hole transport materials?like CuI (PCE: 23.25%), Cu2O (PCE: 19.17%), organic hole transport materials?like spiro-OMETAD (PCE: 23.76%) and PTAA (PCE: 23.74%) to achieve high?efficiency. This simulation model will become a good guide for the fabrication?of high efficiency tin-based perovskite solar. The results show that the lead-free CH3NH3SnI3 is a potential environmentally friendly solar cells with high efficiency.
文摘Numerical simulation has been used to investigate the effect of different buffer?layer components on the performance of CuInGaSe2?solar cells?with SCAPS-1D?software. The main photovoltaic parameters of simulated devices: open-circuit?voltage (Voc), short-circuit current (Jsc), fill factor (FF), and conversion efficiency (h),?areanalysed as a function of thickness and temperature in the different buffer layers used. According to numerical simulation the highest conversion?efficiency (23%) of CIGS solar cell is reached for the CdS buffer layer. This?result is validated by experimental results?(20%). At 300 K, when the thickness?of?the buffer layer (CdS, ZnS, ZnSe,?InSe2) increases from 100 nm to 500?nm,?with the other parameters maintained constant, the efficiency decreases. When the temperature increases from 300 K to 400 K,?with the other parameters maintained?constant, both open circuit voltage and conversion efficiency also decrease.?The?effect of dual buffer layers of ZnS/CdS has also been analysed and his efficiency increases?of 3% than a single buffer CdS.
