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Dye-sensitized/organic solar cells (DS/O-SCs) have gradually improved their power conversion efficiencies (PCEs) and are now being considered for commercialization. This comprehensive review focuses on a prominent class of small organic molecules called triphenylamines (TPAs), which are extensively utilized in DS/O-SCs due to their low cost and facile synthestic procedures. Specifically, we aim to explore state-of-the-art experimental strategies for synthesizing TPA derivatives as efficient sensitizers. These sensitizers have demonstrated the ability to significantly enhance the PCE of DS/O-SCs by over 10%. The insights gained from this review will contribute to advancing the rational design of TPA-based DS/O-SCs, paving the way for potential commercial applications in the near future.|Highly efficient small organic triphenylamines (TPAs) molecules used in DSCs and OSCs with their cost-effectiveness and straightforward synthesis methods.

Halide perovskites are compelling candidates for the next generation of clean-energy-harvesting photovoltaic technologies owing to an unprecedented increase in power conversion efficiency and their low cost, facile fabrication and outstanding semiconductor properties. The potential of perovskite materials has been identified by understanding the fundamental science of perovskites such as crystallisation dynamics and charge carrier dynamics and finding various novel perovskite combinations from the periodic table. Current evidence suggests that the synthetic approach applied for the deposition of halide perovskite layers is a key factor dictating device efficiency and stability. In this review, we aim to investigate the large variety of synthetic procedures followed for the deposition of perovskite polycrystalline films and single crystal layers. We will summarize the current understanding and ability to influence material properties by using these synthetic methods and explore the link between synthetic approaches and material properties relevant to photovoltaic and other applications.|Halide perovskites are compelling candidates for the next generation of photovoltaic technologies owing to an unprecedented increase in power conversion efficiency and their low cost, facile fabrication and outstanding semiconductor properties.

Neuromorphic computing requires electronic systems that can perform massively parallel computational tasks with low energy consumption. Such systems have traditionally been based on complementary metal-oxide-semiconductor circuits, but further advances in computational performance will probably require devices that can offer high-order complexity combined with area and energy efficiency. Halide perovskites can handle both ions and electronic charges, and could be used to create adaptive computing systems based on intrinsic device dynamics. The materials also offer exotic switching phenomena, providing opportunities for multimodal systems. Here we explore the development of neuromorphic hardware systems based on halide perovskites. We examine how devices based on these materials can serve as synapses and neurons, and can be used in neuromorphic computing networks. We also consider the challenges involved in developing practical perovskite neuromorphic systems, and highlight how these systems could augment and complement digital circuits.|This Review examines the development of neuromorphic hardware systems based on halide perovskites, considering how devices based on these materials can serve as synapses and neurons, and can be used in neuromorphic computing networks.

The interface tailoring is crucial for the efficiency and stability of Perovskite Solar Cells (PSCs). The reported interface engineering primarily focuses on the energy level turning and trap state passivation to improve the photovoltaic performance of PSCs. In this review, molecule modifications are classified according to the basics of electron transfer mechanisms for the interface tailoring of materials. An in‐depth analysis of energy level modification and trap passivation, as well as the universal Density Functional Theory (DFT) method employed in interface tailoring. In addition, strategies to address environmental protection and large‐scale mini‐modules fabrication by interface engineering are also discussed. This review can guide the researchers in understanding interface engineering to design interface materials for efficient, stable, and eco‐friendly PSCs.

Perovskite solar cells are among the most dominant emerging PV technologies which have shown unparallel improvement in power conversion efficiency in just over a decade. Long charge carrier diffusion lengths and lifetimes, high absorption coefficients, band gap tunability, and defect tolerance characteristics make them remarkable optoelectronic materials. However, the process of fabricating perovskite solar cells is very extensive and complex creating hindrance to the scaling-up of the solar cells. Plethora of choices for materials, processes, cell configurations, and storage environment or stabilizing period needs to be evaluated for different layers and steps involved in the complete fabrication of these cells. This study addresses the evaluation of decision variables for the complete fabrication of these cells with different objectives that need to be accounted at the experimentation stage along with detailed insights into different process steps. This evaluation of the entire process will be necessary for going forward for multi-objective optimization of the perovskite solar cell production which not only provides good efficiencies but also involves low energy-intensive fabrication processes like solution-based techniques, low-cost materials, and low-environmental impact. Along with this goal of critically evaluating the process design for perovskite solar cells, the study also suggests mechanistic models at different steps which can be employed to enhance the screening process for fabricating these cells. Finally, a framework for employing mathematical decision modeling towards this goal is presented which has the potential for coupling with machine learning (ML) and artificial intelligence (AI) based techniques for rapid screening of the decision variables space.

Although the power conversion efficiency of perovskite solar cells (PSCs) has reached 25.7%, there is still great potential for improvement in their performance and stability. In the past few years, ionic liquids (ILs) have been extensively investigated and demonstrated to enhance the efficiency and stability of devices substantially. Herein, the role of ILs in PSCs as additives, solvents, interface engineering, and charge transport layer is reviewed. Also, this review will guide the researchers in understanding bulk doping and interface engineering for efficient and stable PSCs.

Neuromorphic computing requires electronic systems that can perform massively parallel computational tasks with low energy consumption. Such systems have traditionally been based on complementary metal-oxide-semiconductor circuits, but further advances in computational performance will probably require devices that can offer high-order complexity combined with area and energy efficiency. Halide perovskites can handle both ions and electronic charges, and could be used to create adaptive computing systems based on intrinsic device dynamics. The materials also offer exotic switching phenomena, providing opportunities for multimodal systems. Here we explore the development of neuromorphic hardware systems based on halide perovskites. We examine how devices based on these materials can serve as synapses and neurons, and can be used in neuromorphic computing networks. We also consider the challenges involved in developing practical perovskite neuromorphic systems, and highlight how these systems could augment and complement digital circuits. This Review examines the development of neuromorphic hardware systems based on halide perovskites, considering how devices based on these materials can serve as synapses and neurons, and can be used in neuromorphic computing networks., Funding Agencies|Ministry of Science and ICT, Korean Government (NRF-2021R1A2C3005401). [NRF-2021R1A2C3005401]; Ministry of Science and ICT through the National Research Foundation - Korean Government [101092702]; European Commission under the Horizon Europe Programme, through funding of the OASEES project

The integration of thin 2D perovskite layers at the 3D PVK/HTL interface is known to improve the power conversion efficiency and stability of perovskite solar cells (PSCs). In this work, we report a novel approach consisting of mixing two alkyl-based cations that form 2D perovskites (propylammonium iodide (PAI) and octyl ammonium iodide (OAI)) to form mixed cation 2D halide perovskite layers. The solar cells containing the mixed cations demonstrate enhanced device stability retaining 95% of performance after 1000 h under maximum power point tracking, far exceeding PSC samples with single OAI, 88% and PAI, 80% 2D layers. By cation mixing, the formation of a novel 2D perovskite crystal structure was confirmed by XRD and PL analysis and it was shown to have a uniform quasi-2D state (n = 2), a feature not found in single OAI and PAI samples. Notably, the novel morphology of the crystal structure leads to improved carrier dynamics and enhanced PSC stability.

Triarylamine end-capped-functionalized arylene-imidazole derivatives were synthesized from readily accessible, inexpensive precursors and employed as hole transporting materials (HTMs) in perovskite solar cells (PSCs). All the HTMs displayed high thermal decomposition temperatures (>410 °C), which is beneficial for realizing stable PSC devices. In addition, the new HTMs show appropriate energy level alignment with the perovskite layer, ensuring efficient hole transfer from perovskites to HTMs. Interestingly, PSCs fabricated with the triarylamine-functionalized imidazolyl-capped bithiophene molecule (DImBT-4D) as the HTM exhibited the best power conversion efficiency of 20.11%, comparable to that of the benchmark HTM spiro-OMeTAD, prompting it be a prospective candidate for large-scale PSC applications.

Metal-halide perovskites are optoelectronic materials applied to solar cells as a light absorber due to their excellent optoelectronic properties. The power conversion efficiency of perovskite solar cells (PSCs) reaches 25.7% certified, which stands in comparison with Si solar cells. Importantly, compositional engineering of perovskites has been one of the keys to the breakthrough. However, the presence of defects within perovskites is a matter of importance as it can cause nonradiative recombination of charge carriers. In addition, defect migration can degrade the photovoltaic performance and stability of PSCs. Previous studies have commonly addressed that iodide-related defects such as interstitial iodide and iodide vacancy are problematic due to their low formation energy. Thus, halide engineering is imperative to mitigate the defect-related dynamics and improve the materials quality of perovskites. In this sense, superhalogen is a promising candidate for defect passivation and stabilization of perovskites based on its higher electronegativity and electron affinity than halides, which are beneficial to the formation of a more robust interaction with adjacent elements in perovskites. This perspective gives an overview of studies regarding the use of superhalogen to develop efficient and stable PSCs and concludes with an outlook of further research directions.