RESUMO
Lead-based halide perovskite materials are being developed as efficient light-absorbing materials for use in perovskite solar cells (PSCs). PSCs have shown remarkable progress in power conversion efficiency, increasing from 3.80% to more than 25% within a decade, showcasing their potential as a promising renewable energy technology. Although PSCs have many benefits, including a high light absorption coefficient, the ability to tune band gap, and a long charge diffusion length, the poor stability and the toxicity of lead represent a significant disadvantage for commercialization. To address this issue, research has focused on developing stable and nontoxic halide perovskites for use in solar cells. A potential substitute is halide double perovskites (HDPs), particularly vacancy-ordered HDPs, as they offer greater promise because they can be processed using a solution-based method. This review provides a structural analysis of HDPs, the various synthesis methods for vacancy-ordered HDPs, and their impact on material properties. Recent advances in vacancy-ordered HDPs are also discussed, including their role in active and transport layers of solar cells. Furthermore, valuable insights for developing high-performance vacancy-ordered HDP solar cells are reported from the detailed information presented in recent simulation studies. Finally, the potential of vacancy-ordered HDPs as a substitute for lead-based perovskites is outlined. Overall, the ability to tune optical and electronic properties and the high stability and nontoxicity of HDPs have positioned them as a promising candidate for use in photovoltaic applications.
RESUMO
Nowadays, the emissions from the diesel engines are focused lot to minimise the environmental pollutions in accordance with the emission standards. In this regard, biodiesels are found to be efficient for the diesel engines due to their higher energy contents and low exhaust emissions. Use of biofuel in association with diesel will be an efficient way for the cost-effective performance of the diesel engines with reduced pollutions. The COME is an efficient combustible oil, in which the diesel is blended at different proportions to identify their suitability in the diesel engines. In this regard, the properties of the COME-Diesel blends are determined and analysed for their influence on the combustion characteristics. To understand the performance and emission characteristics of blends, experiments are carried out on the variable compression ratio (VCR) engine keeping the blend, compression ratio, load, and speed as variables. The response surface methodology (RSM) used as a tool for designing and conducting the experiments according to the predetermined variables. The experimental sets generated are performed to determine the NO and HC emissions (response functions). The adequacy of the models is verified through ANOVA and through the p and F tests. The experimental design matrix is also used in training the artificial neural network (ANN) to develop the empirical models. The models from RSM and ANN are experimented and the results obtained from both the models are compared for their accuracy levels. Once the hypothesis is developed for the biodiesel and engine setup, the emission models will be used for the optimising the engine operating parameters and blends to minimise the pollutions from engine for wide operating conditions.
