Contact selectivity is a key parameter for enhancing and improving the power conversion efficiency (PCE) of crystalline silicon (c-Si)-based solar cells. Carrier selective contacts (CSC) are the key technology which has the potential to achieve a higher PCE for c-Si-based solar cells closer to their theoretical efficiency limit. A recent and state-of-the-art approach in this domain is the tunnel oxide passivated contact (TOPCon) approach, which is completely different from the existing classical heterojunction solar cells. The main and core element of this contact is the tunnel oxide, and its main role is to cut back the minority carrier recombination at the interface. A state-of-the-art n-type c-Si-based TOPCon solar cell featuring a passivated rear contact was experimentally analyzed, and the highest PCE record of ~25.7% was achieved. It has a high fill factor (FF) of ~83.3%. These reported results prove that the highest efficiency potential is that of the passivated full area rear contact structures and it is more efficient than that of the partial rear contact (PRC) structures. In this paper, a review is presented which considers the key characteristics of TOPCon solar cells, i.e., minority carrier recombination, contact resistance, and surface passivation. Additionally, practical challenges and key issues related to TOPCon solar cells are also highlighted. Finally, the focus turns to the characteristics of TOPCon solar cells, which offer an improved and better understanding of doping layers and tunnel oxide along with their mutual and combined effect on the overall performance of TOPCon solar cells.

Evaluation of fire hazard caused by electrical installations is a difficult and important topic, and it limits the possibility of loss of life or health of people, as well as the occurrence of significant property damage. In particular, this hazard was caused by power cables and especially photovoltaic (PV) installations. The authors proved that power cables directly exposed to strong solar radiation are likely to exceed maximum permissible temperature in unfavorable ambient conditions. Overheated and damaged cable insulation can be a source of electric shock and a strong leakage current causing fire. In the case of typical PV connectors (MC4 connectors), the main problem is poor contact at the connections of the PV cables. A poor connection can even cause the connector to melt, as shown in this study. In the paper, the authors present a computer simulation regarding critical thermal points of electrical installations, in particular, of the PV type. It may be an indication of what should be paid attention to when designing and implementing such installations. This is important for the safety of people and buildings.

Contact selectivity is one of the key requirements for maximizing the efficiency of solar cells. Here, we computationally explore the electron-selective contact for crystalline silicon (c-Si) solar cells based on TiO ₂ and its stacked combinations with amorphous silicon or SiO ₂ passivation layers. The relative effectiveness of these contact schemes is quantified under practical concerns of Fermi-level pinning (FLP) and interfacial defects. For a standard TiO ₂ /Al contact stack on c-Si, a relatively high Schottky barrier (~0.5 eV) typically exists due to FLP which can increase the series resistance and degrades fill factor (FF) at low-to-moderate doping in TiO ₂ . With the insertion of an ultrathin SiO ₂ layer, the SiO ₂ /TiO ₂ /Al stack can mitigate the parasitic Schottky effect on series resistance through its better pinning factor, resulting in ~5% absolute increase in the FF. Moreover, by introducing a field-effect passivation through the SiO ₂ layer, the surface concentration of the minority carriers can be suppressed and the associated surface recombination losses can be minimized for interfacial defect density up to ~1× 10 ¹² cm ^-2 eV ^-1 . In contrast, the cell performance for TiO ₂ /Al stack degrades due to surface recombination losses for interfacial defect density above ~1 × 10 ¹⁰ cm ^-2 eV ^-1 . These quantitative insights provide valuable understanding of the published experimental data and provide useful guidelines for the design of TiO ₂ -based contact stacks.

Indoor photovoltaics (IPV) has recently emerged as a sustainable and reliable energy technology to power the rapidly growing Internet of Things. Among various solar cell technologies, emerging perovskite solar cells (PSCs) have gained great interest for IPV; owing to their unique optoelectronic properties such as bandgap tunability to efficiently harvest the indoor light spectrum. The choice of hole transport layer (HTL) is critical for efficient PSCs, particularly in IPV applications to reduce the parasitic absorption losses in the indoor light spectrum. Here, we explore the potential of CuSCN to be used as a HTL for PSCs in IPV applications. We show that CuSCN-based PSC exhibits remarkable power conversion efficiency ( η ) as compared to PSCs using conventional PEDOT:PSS as HTL. We explore the effects of wavelength ( λ ) of incident photons and various design parameters of PSC for optimal cell operations. We show that at a particular perovskite thickness, CuSCN-based PSC exhibits ∼8%–12% higher η than that for PEDOT-based PSC, for all λ in the visible range of the spectrum. We further explore the effect of HTL doping/thickness on PSC performance and show that CuSCN-based PSC performs optimally for a wide range of doping/thickness of HTL. We also find that CuSCN-based PSC outperforms PEDOT-based PSC for a broad range of incident irradiance. Finally, we show that for large values of λ (i.e. λ = 700 nm), η exceeds 30%, close to the highest ever in the past work. The work presented in this study will provide guidance for the development of efficient PSCs for indoor applications.

The increasing penetration of distributed energy resources, the variability of renewables, and climate disruptions make community microgrids key to modern low-voltage distribution networks. Integrated energy management systems coordinate generation, storage, and loads to enhance resilience, sustainability, and efficiency. In this paper, we summarize significant technological and methodological advances in integrated energy management systems for community microgrids, covering conceptual foundations, architectural models, and enabling technologies. We compare centralized, decentralized, and hybrid-hierarchical control frameworks using quantitative criteria, including computational complexity, communication overhead, failure-recovery time, and the demonstrated maximum distributed energy resources count. We also examine the convergence of supervisory control and data acquisition, energy management systems, and distributed energy resource management systems platforms over the IEC 61850 and IEEE 2030.5 communication protocols. We review AI methods for forecasting, optimization, and control, including long short-term memory, convolutional neural networks, and hybrid models that reduce mean absolute percentage error. We examine model predictive control and reinforcement learning for decision-making. In addition, we examine the challenges of integrating renewable energy sources and storage solutions. Resilience mechanisms are reviewed within a unified framework covering voltage and frequency stability, black-start, islanding, and cyber-resilience against false-data-injection and denial-of-service attacks. Through this study, we identify key research gaps and suggest future directions for scalability, interoperability, cybersecurity, and sociotechnical integration that will help researchers, practitioners, and policymakers to develop resilient and sustainable community microgrids.