This PDF file contains the front matter associated with SPIE Proceedings Volume 13027, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Stability in perovskite solar cells (PSCs) is a topic heavily studied by the research community in recent years, despite the impressive efficiencies achieved with these remarkable optically-active materials for photovoltaics (PV) applications. Specifically, moisture ingress and ion-transport need to be reduced to attain a lifetime sufficient for a commercially viable PV technology. The stability issues arise from a number of factors, including the susceptibility of the absorber to environmental conditions. In this work, we will discuss our efforts to examine the stability in PSCs from multiple angles, which include examining the role of interface layers, collector electrode material used, and the chemistry and crystalline structural of the absorber itself.

We have developed comprehensive and simulation tools that can reliably predict performance of thermo-radiative (TR) devices. Based on simulations and characterization, we have identified that the inefficient photon extraction from Hg_1−xCd_xTe is the main obstacle of achieving high-performing TR devices. We have designed photonic structures to significantly improve photon extraction from Hg_1−xCd_xTe, which promises order-of-magnitude TR performance improvement.

This study introduces a successful modification of the bipolar electrochemistry (BPE) method to efficiently produce and deposit high-quality reduced graphene oxide onto a conductive substrate. This innovative approach integrates material production and device fabrication into a single-step process that is straightforward, controllable, cost-efficient, and environmentally friendly. Microstructural analysis of the deposited material reveals the formation of oriented graphene sheets on the substrate. For micro-supercapacitor fabrication, interdigitated gold microelectrode arrays are generated through regular photolithography and subsequently employed as the conductive substrate in the BPE process. The electrochemical assessment of the fabricated device through cyclic voltammetry and galvanostatic charge/discharge verifies its outstanding specific areal capacitance. Notably, electrochemical impedance spectroscopy unveils exceptional high-frequency responses, promising potential applications in AC/DC filter systems. A comprehensive presentation of the detailed results will be delivered at the upcoming conference.

The U.S. Army’s climate and modernization priorities are driving significant improvements in the U.S. Army’s capabilities, while multi-domain operations (MDO) are driving a need for substantial improvements to legacy and future systems that support a more comprehensive operational range and can be pushed harder, faster, and for longer periods. For the foreseeable future, the U.S. Army and its allies will rely on devices that utilize some form of the internal combustion engine (ICE). In the interim, however, hybrid technology has received much interest as ICEs can be combined with other dissimilar energy generation, transmission, load, and storage possibilities, including fuel cells, photovoltaics, and decaying radioisotopes. Fundamentally making a hybrid device a self-contained energy network or microgrid. This paper investigates the operational use of a hydrogen fuel cell-supported tactical energy network that includes photovoltaic arrays and electrochemical energy storage. Energy harnessed from the solar arrays can be used to split water molecules, forming hydrogen and oxygen while energy demand is low; conversely, if energy demand is high, the fuel cell may also supply energy. Fuel cell systems have reduced acoustic and thermal signatures compared to ICEs, making such technology an ideal candidate for civilian and military applications, especially where water is abundant and can be dependably harvested. Hydrogen production and water consumption of a fuel cell are analyzed subject to three characteristic sky conditions: clear, partly cloudy, and overcast sky conditions. Two optimization strategies were explored and used to optimally control the energy networks to extend the energy network’s operation, which was limited by the water reservoir and atmospheric conditions.

Energy harvesting using various locally available energy sources such as vibration energy, heat, sound, or magnetic field have become attractive topics for supplying power to modular electronic devices making them run independently in extreme environments. In this paper, we will be discussing the perspectives on thermoelectric (TE) and piezoelectric materials and devices, and then the concept of multi-source energy harvester using piezoelectric and thermoelectric devices and integration of them into a reliable and independent power source. TE materials having low thermal conductivity and high figure-of-merit (zT) are developed to convert even a small temperature gradient efficiently into electrical energy with the state-of-the-art conversion efficiency of ~15% and output power of ~56W from single device. The piezoelectric device architecture is configured using high performance piezoelectric ceramics (Cu-Mn-PIN-PMN-PT). These ceramics exhibit high piezoelectric coefficient with high mechanical quality factor and low dielectric loss factor. Using these piezoelectric materials, power density as high a 2mW/cm² is demonstrated in 1-1.5g vibration environments. The piezoelectric device is attached on the surface of TE module to capture both the vibration and thermal energy sources to realize dual mode energy harvester. The multi-energy transfer strategy opens opportunities for a future generation of wireless and modular electronic devices. These devices would be useful in powering wearable electronic devices, micro sensor chargers, etc. in extreme environmental conditions using body heat/thermal sources and induced motion/vibrations.

To harvest both light and heat for sensor applications, we present a theoretical investigation using first-principles calculations on monolayer MoS² to exploit its electronic and optical properties, within and beyond the visible spectrum. By increasing doping concentrations of Ta in monolayer MoS², we achieve a modulating band gap to capture the entire lower energy visible spectrum, extending deep into the infrared region, in contrast to strain engineering where only corrections in band gap can take place. By calculating the Seebeck coefficient, we explore a heat-absorbing aspect of energy harvesting through a reduction in the band gap, dragging the operating wavelengths into the infrared region with a change in the direct nature of the band gap to an indirect while within the visible spectrum. The results provide comprehensive information and open up a way to employ Ta-doped monolayer MoS² in photovoltaic sensing applications.

Within the process of development of sustainable energy solutions, the Ensemble Kalman Filter (EnKF) holds an allimportant key by assisting in forecasting and optimization of renewable energy systems. This essay describes in detail how the EnKF is utilized in diverse sectors of the renewable energy, of which one of its many vital roles is managing the variability and uncertainty that characterize wind and solar energy sources. By performing a meta-analysis and bibliometric work we discover that EnKF do two things very well – the level of the predictive model accuracy is increased and it is also easy to allocate the resources. Grid stability is another issue which EnKF solves well. The versatility of EnKF in wind forecasting has been highlighted in light of a study which has not only demonstrated how this method may be applied in renewable energy sources but also sheds light on recent developments as well. We will leave the forward part to researching potential additional studies such as EnKF integration with machine learning methods and its use towards renewables recent development. The work above shows how EnKF capable advanced data assimilation methods are highly needed for phasing out fossil fuels and ensure the shift to renewable energy sources as the global primary energy source.

Methyl ammonium lead iodide (MAPbI₃) was one of the earliest perovskite formulations examined, which created tremendous interest in these materials given their stupendous rise in power conversion efficiency (PCE). Beyond MAPbI₃, new perovskite formulations have emerged, such as the triple cation (Cs_0.05FA_0.79MA_0.16PbI_2.45Br_0.55) absorbers, which have further advanced research in emerging photovoltaics in addition to other types of optoelectronics sensors. Given the stability issues with many of the perovskites, here we explore how the environmental ambient influences the device stability through in-use testing.

Capacitive deionization (CDI) is an emerging technique for removing dissolved, charged species from aqueous solutions. It has been previously applied to brackish water and seawater desalination, wastewater remediation, and water softening. The CDI unit cell comprises two parallel electrode sheets separated by a non-conductive spacer (nylon cloth, 100 mm thick) and fixed with a rubber gasket. The electrodes are typically carbon, and the feed water flows between or through the two charged electrodes. The porous electrode pair is accused of an applied voltage difference (called the cell or charging voltage). Optimizing the CDI electrode features is essential for scaling up the technique to an industrial scale. The effect of the water flow rate and the applied voltage are key factors that affect the efficiency of the CDI units. This research used Artificial Intelligence (AI) as a smart-based modeling tool to optimize and predict the highest efficiency concerning the electrode and process parameters. The results showed that a carbon-based structure with super-electrochemical and mechanical properties could revolutionize CDI technology.