Mass quantity of population, emission from conventional power plant, and more demand than supply i.e. load shedding encouraged us to search alternative way to fulfill the energy crisis of humankind and reduce greenhouse gas emission. In this paper, we just study the feasibility of energy from outdoor fan of air conditioning system using small wind turbine (rotor radius 0.25-5m), because nowadays air conditioning is the second largest energy consumption device among commercial as well as home appliances in Bangladesh due to climates fluctuation. Moreover, the extracted energy will store in electrochemical device to use this energy during load shedding. It not only helps to reduce tariff but also remove power cut-off tension and replace high price heavy and solar irradiance dependent on-grid rooftop solar system. We measured the outdoor fan's wind speed using anemometer of various capacities such as 1 to 2 tons' air conditioners. Later the model's performance analyzes numerically by MATLAB software. It shows maximum mechanical power 40W at trip speed ratio 8. In addition, cost analysis has done to know economic feasibility.
Quantum efficiency of a SiGe solar cell has been developed for box, triangular and trapezoidal dosing profiles of Ge in exponentially doped base. The doping dependency of carrier mobility and carrier lifetime, the band-gap narrowing effect due to heavy doping level and velocity saturation effects are considered to deduce the governing differential equation for this model. An elegant exponential approximation technique has been employed to simplify the complicated nature of variable coefficients of the working differential equation. The model results show that the increased Ge-content in the base results in significant improvement in the internal quantum efficiency.
Perovskite materials are getting attention day by day due to their numerous optoelectronic properties. Lead perovskites are well-known for various applications in photovoltaic devices due to their non-toxicity which has no impacts on both the environment and health. Cs2PtI6, a lead-free halide perovskite, is renowned for its broad-spectrum light absorption and remarkably high absorption coefficient. Its stability under ambient conditions surpasses that of numerous other halide perovskites, rendering it exceptionally appealing for photovoltaic applications The device configuration with FTO/ETL/Cs2PtI6/HTL/Au is used in this study where 4 different ETLs and 10 HTLs are used to investigate the best device configuration. The impact of different device parameters like thickness, acceptor density, donor density, and defect density are optimized to attain the best efficient device configuration. SCAPS-1D simulator is used to perform numerical analysis under light intensity of AM 1.5 light spectrum (100 mW/cm2). After the optimization of different device parameters, the device configured with FTO/SnS2/Cs2PtI6/MoTe2/Au shows the best performance among four devices where PCE is 32.98 %, VOC is 1.11 V, JSC is 33.19 mA/cm2, FF is 88.89 %. This suggested Cs2PtI6-based perovskite solar cells demonstrate superior performance compared to numerous lead perovskite-based solar cells, highlighting Cs2PtI6 as a promising alternative for photovoltaic applications while mitigating toxicity concerns.
Abstract In the backdrop of today's environmental priorities, where toxicity and stability hinder lead‐based perovskite solar cell (PSC) progress, the emergence of lead‐free alternatives like Cs 2 AgBiBr 6 perovskites has gained significance. This study revolves around the comprehensive evaluation of Cs 2 AgBiBr 6 as a potential photovoltaic (PV) material, using density functional theory (DFT) calculations with CASTEP. Revealing a vital bandgap of 1.654 eV and emphasizing the contributions of Ag‐4 d and Br‐4 p orbitals, this analysis also underscores Ag atoms' dominance in charge distribution. Optically, Cs 2 AgBiBr 6 exhibits UV absorption peaks around 15 eV, intensifying with photon energy up to 3.75 eV, hinting at its promise for solar applications. Guided by DFT, forty configurations involving various electron transport layers (ETLs) and hole transport layers (HTLs) are explored. Among these, CNTS emerges as the prime HTL due to ideal absorber alignment. The spotlight architecture, FTO/AZnO/Cs 2 AgBiBr 6 /CNTS/Au, boasts exceptional efficiency (23.5%), V oc (1.38 V), J sc (21.38 mA cm −2 ), and FF (79.9%). In contrast, FTO/CdZnS/Cs 2 AgBiBr 6 /CNTS/Au achieves a slightly lower 23.15% efficiency. Real‐world intricacies are probed, encompassing resistances, temperature, current–voltage ( J – V ) traits, and quantum efficiency (QE), enhancing practical relevance. These findings are thoughtfully contextualized within prior literature, showcasing the study's contributions to non‐toxic, inorganic perovskite solar technology. This work aspires to positively steer sustainable PV advancement.
The CIGSSe-based solar cell with a thin structure of Al/ZnO/ZnMnO/CIGSSe/Cu2O/Ni has been optimized for photovoltaic (PV) performance using SCAPS-1D software. The solar cell design incorporates a CIGSSe absorber layer, a zinc manganese oxide (ZnMnO) buffer layer, and a zinc oxide (ZnO) window layer that acts as a transparent conductive oxide (TCO). The upper/top and back contacts are made of aluminum (Al) and nickel (Ni), respectively, with an electron reflected-hole transport layer (ER-HTL) of cuprous oxide (Cu2O) between the back metal contact and the absorber layer. By adjusting the thicknesses of the absorber, buffer, and window layers, acceptor and donor densities, series and shunt resistance, and temperature, the performance of the proposed structure can be enhanced. By employing less hazardous components and incorporating several layers, the configuration enhances the cell structure's open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and efficiency (η). Consequently, the suggested cell architecture demonstrates an exceptional efficiency of 38.84% for the AM1.5G spectrum and exhibits a quantum efficiency of nearly 95.33% at visible wavelengths. The findings demonstrate the potential of the proposed solar cell design for high-performance and environmentally friendly PV applications.
The photovoltaic (PV) cell structure containing Al/ZnO/CdS/CdTe/Cu2O/Ni has been simulated using the SCAPS-1D software. The PV device includes a zinc oxide (ZnO) transparent conductive oxide (TCO) window layer, a cadmium sulfide (CdS) buffer layer, and a cadmium telluride (CdTe) absorber layer. Additionally, an electron reflected-hole transport layer (ER-HTL) comprising cuprous oxide (Cu2O) is introduced between the absorber layer and the back metal contact. Aluminum (Al) and nickel (Ni) serve as the upper/top and back contact materials, respectively, interconnecting the layers. The back contact materials, the thickness of the absorber, buffer, and window layers, the acceptor density of the absorber layer, the donor density of the buffer layer, the series and shunt resistance, as well as temperature, were all modified to investigate the PV performance of this structure. The PV performance parameters are evaluated through the open-circuit voltage (VOC), short-circuit current (JSC), fill factor (FF), and power conversion efficiency (PCE). To achieve optimal performance, it is recommended to set the acceptor and donor densities for the absorber and buffer layers at 1017 cm-3. These desired densities can be attained by using a window and buffer layer thickness of 100 nm, an absorber layer thickness of 2500 nm, and an ER-HTL of 50 nm. The optimized model demonstrates PV performance characteristics of 1.4811 V for VOC, 28.682434 mA/cm2 for JSC, 74.91% for FF, and 31.82% for PCE under the AM1.5 G spectrum. Furthermore, it exhibits a quantum efficiency of around 100% at visible wavelengths.
In recent times, the air quality level of Dhaka city has been termed as hazardous. The weather of Dhaka city has gone through some drastic changes because of extreme air pollution. In this paper, we have applied several machine learning models that include deep learning such as Long Short-Term Memory (LSTM) and proposed different techniques to forecast the air quality level of Dhaka city. Furthermore, we demonstrate the applicability of machine learning and deep learning models in the classification and prediction of the Air Quality Index (AQI) based on some pre-determined range. The novelty of this approach is that we have considered daily temperature as a parameter for air pollution prediction. We conduct an extensive evaluation of these models and show that different machine learning models can classify the AQI of different places of Dhaka city. LSTM models can also forecast hourly and daily AQI with optimal performance.
Abstract In recent times, the remarkable advancements achieved in the field of perovskite solar cells (PSCs) have sparked significant research efforts aimed at enhancing their overall performance because of their exceptional optoelectronic properties. Due to the toxicity of lead (Pb), the emergence of Ti‐based (Cs 2 TiBr 6 ) double‐halide PSCs is regarded as a good alternative to Pb‐based PSCs. Here, density functional theory (DFT) calculations are performed to examine the prospect of Cs 2 TiBr 6 perovskite as a layer of absorber for photovoltaic cells (SCs). These computations looked at the material's structural, optical, and electrical characteristics. The density of states (DOS) results demonstrate strong conductivity, principally provided by the 4p states of Br, whilst Ti‐3d and Cs‐5p orbital electrons offer insignificant contributions. The electronic band structure discloses a direct band gap of 1.534 eV. The covalent connections that exist between Ti and Br atoms and the robust electronic charge density around the Ti atom both demonstrate a significant buildup of electronic charge along the 100 planes. The dielectric function and the coefficient of absorption have significance irrespective of lower energies because it is extremely valuable for solar energy applications. The UV absorption peaks of Cs 2 TiBr 6 have a maximum of ≈15.51 eV and are magnified with photon energy up to 2.46 eV, indicating that it may have potential for solar applications. This work also investigated a good combination of the hole transport layer (HTL) and electron transport layer (ETL) with the Cs 2 TiBr 6 absorber layer. AZnO, Nb 2 O 5 , LBSO, and Zn 2 SnO 4 are executed as the ETLs, and MoO 3 , CuAlO 2 , MEH‐PPV, ZnTe, CNTS, GaAs, MoS 2 , PTAA, Cu 2 Te, Zn 3 P 2 are considered as the HTLs to identify the best HTL/Cs 2 TiBr 6 /ETL combinations using the SCAPS‐1D numerical simulation. Among all configurations, ITO/LBSO/Cs 2 TiBr 6 /CNTS/Au is examined as the best‐optimized structure of Ti‐based PSC, with J SC of 26.63 mA cm −2 , a V OC of 1.123 V, FF of 82.94%, and a power conversion efficiency of 24.82%. To validate the findings, PV parameters like the effect of generation rate, recombination rate, J−V, and Q‐E characteristics are evaluated. The effect of series and shunt resistance and structure working temperature are explored to observe the effect of these on PSC devices. The accomplished outcomes suggest that Cs 2 TiBr 6 can be viewed as an optimistic material for PSCs for its higher stability and environment‐friendly characteristics.
