V. Parkavi, K. Narendra, Mohammed Faazil, K. Jayabal, Pandiyarasan Veluswamy
The utilization of solar integrated thermoelectric technology plays a crucial role in addressing the global energy crisis. Enhancing the performance of the integrated technology can be achieved by introducing a photothermal layer. This layer consists of a photothermal material that exhibits broad solar absorption, including the near-infrared (IR) region. Wide-bandgap 2D semiconductor materials were used as the photothermal material. The integration shows better performance than other conventional techniques. This work includes an evaluation using COMSOL, a computational technique. Simulation models were developed and used to predict performance under various solar irradiance conditions. Results were predicted for electrical parameters and found to be 6.2 V produced by an individual module, whereas when the photothermal layer is introduced between the integrated technology, the device can produce a voltage of approximately 9 V. These findings include the comparison study of different photothermal materials. Thus, the proposed work involves predicting and optimizing the behavior of the integrated device in various environmental conditions and provides a way to maximize its energy conversion efficiency.
Thermally activated delayed fluorescence (TADF) polymers have emerged as a promising class of emissive materials for solution-processed organic light-emitting diodes (SP-OLEDs) due to their ability to utilize both singlet and triplet excitons for efficient light generation. Recent advances in molecular design, including main-chain donor-acceptor architectures, pendant-type systems, through-space charge transfer structures, and copolymer strategies, have enabled significant improvements in their photophysical and electroluminescent properties. These polymers exhibit favourable characteristics such as high photoluminescence quantum yields, small singlet-triplet energy gaps, and efficient delayed fluorescence, leading to encouraging device performances. In addition, their polymeric nature provides important advantages, including reduced aggregation-caused quenching, excellent film-forming ability, and compatibility with low-cost solution-processing techniques. Despite these benefits, TADF polymers still face limitations compared to small-molecule emitters, particularly in achieving higher external quantum efficiencies and superior colour purity with narrow emission bandwidths. Therefore, continued research focused on molecular engineering, structural optimization, and device design is essential to further enhance their performance and fully exploit their potential for next-generation, high-efficiency SP-OLED applications.
Nurfarhana Ahmad Musri, Angella Th’ng, Izzah Hanim Abd Aziz, Ubaidah Syafiq
Thin film thermoelectric materials have garnered significant attention due to their potential for efficient energy conversion in various applications, ranging from waste heat recovery to wearable electronics to space exploration. This review paper provides a comprehensive overview of recent advancements in thin film thermoelectric materials and devices. The first discusses the fundamental principles governing thermoelectricity and the parameters influencing the thermoelectric performance, such as the Seebeck coefficient, electrical conductivity, and thermal conductivity. Then, it elucidates the unique properties of thin films that make them promising candidates for thermoelectric applications. It then highlights recent developments in novel thermoelectric materials, including conventional inorganic materials such as bismuth telluride, as well as emerging materials like lanthanum (III) telluride. The synthesis methods, including physical vapor deposition, chemical vapor deposition, and solution-based techniques, are further discussed along with their impacts on the structural and electrical properties of thin film thermoelectric materials. The review also highlights recent progress in the fabrication of device and their performances. Finally, future research directions and emerging trends in thin film thermoelectric are outlined to inspire further advancements in this rapidly evolving field.
V. Stanishev, I. Streicher, A. Papamichail, V. Rindert, P. P. Paskov, S. Leone, V. Darakchieva
We present a contactless determination of the two-dimensional electron gas (2DEG) properties in AlScN/GaN and AlYN/GaN high electron mobility transistor (HEMT) structures using the terahertz optical Hall effect (OHE) over a temperature range of 20 K–360 K. The structures are grown on sapphire or 4H-SiC substrates by metalorganic chemical vapor deposition (MOCVD) and feature ∼10-nm thick barrier layers with Sc and Y contents ranging from 4.6% to 17.3% and 3.3% to 8.2%, respectively. The temperature dependencies of the 2DEG density and mobility parameters are analyzed and discussed in a comparative manner. Additionally, conclusions are drawn regarding the predominant scattering mechanisms at both low and room temperatures. Furthermore, the 2DEG effective mass parameter m * in AlScN/GaN and AlYN/GaN is determined for the first time. At low temperatures m * is found to be in the range 0.20 − 0.27 m 0, close to the value of 0.23 m 0 for bulk GaN. As temperature increases above 100 K, m * gradually rises reaching 0.33 − 0.39 m 0 at room temperature, consistent with findings for AlGaN/GaN HEMTs. The underlying causes of this temperature-dependent increase in effective mass are discussed, with a possible explanation linked to polaron effects and deviations from the classical Drude model.
