All layers patterned conical nanostructured thin-film silicon solar cells for light-trapping efficiency improvement.

Thin-film silicon solar cells (TSSC) has received great attention due to its advantages of low cost and eco-friendly. However, traditional single-layer patterned solar cells (SPSC) still fall short in light-trapping efficiency. This article presents an all layers patterned (ALP) conical nanostructured TSSC to enhance the low absorption caused by the thin absorption layers. The Finite-Difference Time-Domain result shows that a photocurrent density up to 41.27 mA/cm2 can be obtained for the structure, which is 31.39% higher than that of the SPSC. An electrical optimization simulation of doping concentration was carried out on the parameters of the optically optimal structure of the model. The power conversion efficiency is 17.15%, which is 1.72 times higher than that of the planar structure. These results demonstrate a success for the potential and prospect of the fully patterned nanostructures in thin-film photovoltaic devices.

Bandgap Engineering and Oxygen Vacancy Defect Electroactivity Inhibition in Highly Crystalline N-Alloyed Ga2O3 Films through Plasma-Enhanced Technology.

Previous research has shown that the hybridization of N 2p and O 2p orbitals effectively suppresses the electrical activity of oxygen vacancies in oxide semiconductors. However, achieving N-alloyed Ga2O3 films, known as GaON, poses a significant challenge due to nitrogen's limited solubility in the material. In this study, a new method utilizing plasma-enhanced chemical vapor deposition with high-energy nitrogen plasma was explored to enhance the nitrogen solubility in the material. By adjusting the N2 and O2 carrier gas ratio, we could tune the thin film's bandgap from 4.64 to 3.25 eV, leading to a reduction in the oxygen vacancy density from 32.89% to 19.87%. GaON-based photodetectors exhibited superior performance compared to that of Ga2O3-based devices, with a lower dark current and a faster photoresponse speed. This investigation presents an innovative approach to achieving high-performance devices based on Ga2O3.

Stable Resistive Switching in ZnO/PVA:MoS2 Bilayer Memristor.

Reliability of nonvolatile resistive switching devices is the key point for practical applications of next-generation nonvolatile memories. Nowadays, nanostructured organic/inorganic heterojunction composites have gained wide attention due to their application potential in terms of large scalability and low-cost fabrication technique. In this study, the interaction between polyvinyl alcohol (PVA) and two-dimensional material molybdenum disulfide (MoS2) with different mixing ratios was investigated. The result confirms that the optimal ratio of PVA:MoS2 is 4:1, which presents an excellent resistive switching behavior. Moreover, we propose a resistive switching model of Ag/ZnO/PVA:MoS2/ITO bilayer structure, which inserts the ZnO as the protective layer between the electrode and the composite film. Compared with the device without ZnO layer structure, the resistive switching performance of Ag/ZnO/PVA:MoS2/ITO was improved greatly. Furthermore, a large resistive memory window up to 104 was observed in the Ag/ZnO/PVA:MoS2/ITO device, which enhanced at least three orders of magnitude more than the Ag/PVA:MoS2/ITO device. The proposed nanostructured Ag/ZnO/PVA:MoS2/ITO device has shown great application potential for the nonvolatile multilevel data storage memory.

The Structural Evolution of Semipolar (11-22) Plane AlN Tem-Plate on m-Plane Sapphire Prepared by Sputtering and High Temperature Annealing.

In this work, the epitaxial semipolar (11-22) AlN was prepared on nonpolar m-sapphire substrate by combining sputtering and high-temperature annealing. According to our systematic measurements and analysis from XRD, Raman spectra, and AFM, the evolution of crystalline structure and morphology was investigated upon increasing AlN thickness and annealing duration. The annealing operation intensively resets the lattice and improves the crystalline quality. By varying the film thickness, the contribution from the AlN-sapphire interface on crystalline quality and lattice parameters during the annealing process was investigated, and its contribution was found to be not so obvious when the thickness increased from 300 nm to 1000 nm. When the annealing was performed under durations from 1 to 5 h, the crystalline quality was found unchanged; meanwhile, the evolution of morphology was pronounced, and it means the crystalline reorganization happens prior to morphology reset. Finally, the annealing treatment enabled a zig-zag morphology on the AlN template along the sapphire [0001] direction in the plane, which potentially affects the subsequent device epitaxy process. Therefore, our results act as important experience for the semipolar nitride semiconductor laser device preparation, particularly for the epitaxy of microcavity structure through providing the crystalline evolution.