Semiconductor Testing

Lamuta, Caterina, et al. Journal of Physics and Chemistry of Solids 116 (2018): 306-312.

Tin selenide (SnSe) has emerged as a promising material for flexible electronics due to its remarkable mechanical properties. This case study reports the direct evaluation of its mechanical characteristics through nanoindentation experiments, focusing on determining its Young's modulus and hardness. The tests reveal that SnSe possesses a Young's modulus of 25.3 GPa and a hardness of 0.82 GPa, providing critical insights into its suitability for flexible applications.

Nanoindentation experiments were conducted using the continuous stiffness measurement (CSM) method with varying loads. Initially, the indentation curve showed no damage, indicated by the absence of pop-in events, ensuring that the material remained intact during testing. As the penetration depth increased, both Young's modulus and hardness stabilized at approximately 25 GPa and 0.8 GPa, respectively, for depths up to 400 nm. However, deeper penetrations resulted in a decrease in hardness, accompanied by pop-in events, signaling material damage.

These findings are crucial for understanding the mechanical resilience of SnSe in real-world applications. The data confirms that SnSe maintains excellent mechanical properties under moderate stresses but may experience degradation under deeper indentations, emphasizing the importance of load management in its practical use in flexible electronics.

Aguilar-Burgoin, Hector Alfredo, et al. Available at SSRN 5030832.

This study investigates the characterization of NiMoO₄ powders as a semiconductor for potential photocatalytic applications. The materials were synthesized using a simple hydrothermal method, with varying Ni:Mo molar ratios (1:1 and 1:1.63). The structural and optical properties were extensively evaluated through X-ray diffraction, Raman spectroscopy, UV-VIS absorption, and diffuse reflectance spectroscopy, alongside photocatalytic tests for methylene blue removal under UV light.

UV-VIS spectroscopy revealed two key absorption edges in the NiMoO₄ samples—one in the UV region around 350 nm, linked to the fundamental absorption edge, and another in the visible range near 425 nm, attributed to nanocrystalline NiMoO₄. Notably, the sample with the 1:1.63 Ni:Mo ratio exhibited a broader absorption band, suggesting a significant effect of the Mo content on the material's optical properties.

The optical band gaps of the samples were calculated using Tauc plots, indicating a direct bandgap of 3.50 eV for the 1:1 Ni:Mo ratio and 3.11 eV for the 1:1.63 ratio. This variation highlights the influence of Mo incorporation on the material's electronic structure, which is critical for optimizing photocatalytic efficiency.

These results emphasize the importance of controlling the synthesis parameters, such as the Ni:Mo ratio, in tailoring the optical properties of NiMoO₄ for enhanced photocatalytic applications.

Luxová, Jana, et al. Materials Science and Engineering: B 313 (2025): 117889.

This study investigates the characterization of Mn-doped SrTiO₃ perovskite, focusing on its potential as a visible light-active semiconductor for photocatalytic applications. The doping of manganese (Mn⁴⁺) was successfully integrated into the SrTiO₃ structure, evidenced by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) analysis. The material exhibited a dark brown color due to enhanced visible light absorption, with a significant reduction in the band gap from 3.32 eV to 2.92 eV, indicating improved photocatalytic activity.

Scanning electron microscopy (SEM) analysis revealed that both undoped and Mn-doped samples exhibited similar microstructures composed of submicron grains, with Mn uniformly distributed across the perovskite lattice. The adsorption capacity of Mn-doped SrTiO₃ was tested using Methylene Blue (MB) dye at pH 10, showing a maximum removal capacity of 310.7 mg/g, slightly outperforming the undoped sample. This enhanced adsorption was attributed to electrostatic interactions between the material's surface and the dye molecules.

These results highlight the significant role of Mn-doping in tuning the optical properties and improving the material's photocatalytic efficiency. The findings underscore Mn-doped SrTiO₃ perovskite's potential for environmental and energy applications, particularly in photocatalytic degradation processes under visible light.