以一位考古学教授在四川自贡恐龙遗址考察引发的遐想为载体，介绍了U-Pb定年法的基本原理，以及样品采集、样品处理后的分析方法和检测结果处理，全面地科普了U-Pb定年法的相关知识。同时，本文介绍了自贡地区的恐龙文化及产业，向读者展现恐龙之都的魔力。

This paper delves into the theoretical mechanisms of the electronic structure and optical properties of aluminum-based semiconductors (AlX, X=N, P, As, Sb) and indium-based semiconductors (InX, X=N, P, As, Sb) as potential materials for optical devices. Band structure calculations reveal that, except for InSb, all other compounds are direct bandgap semiconductors, with AlN exhibiting a bandgap of 3.245 eV. The valence band maximum of these eight compounds primarily stems from the p-orbitals of Al/In and X. In contrast, the conduction band minimum is influenced by all orbitals, with a predominant contribution from the p-orbitals. The static dielectric constant increased with the expansion of the unit cell volume. Compared to AlX and InX with larger X atoms, AlN and InN showed broader absorption spectra in the near-ultraviolet region and higher photoelectric conductance. Regarding mechanical properties, AlN and InN displayed greater shear and bulk modulus than the other compounds. Moreover, among these eight crystal types, a higher modulus was associated with a lower light loss function value, indicating that AlN and InN have superior transmission efficiency and a wider spectral range in optoelectronic material applications.

碲化锰(manganese telluride，MnTe)作为一种新兴的非层状二维材料，因其优异的性质以及在下一代电子和光电子器件中的巨大潜力，而受到研究学者们的广泛关注。然而，目前超薄二维MnTe的可控合成仍然是一个巨大的挑战，这限制了对其基础性质的研究和应用的深入探索。本文采用化学气相沉积方法成功合成了大面积的MnTe纳米片，并探究了其厚度对电学性质和器件应用的影响。通过提高MnTe纳米片的生长温度，样品厚度逐渐增加，晶畴尺寸从10 μm增至125 μm，形貌从三角形逐渐过度到六边形，最终生长成高度对称的圆形。结构表征和二次谐波测试表明，所制备的MnTe纳米片具有高度的结晶质量和优异的二阶非线性光学性质。此外，通过对不同厚度MnTe纳米片的电学输运测试，发现随着厚度从薄到厚，其导电特性从p型半导体逐渐转变为半金属。因此，利用半导体特性的薄层MnTe纳米片构建的光电探测器展现出出色的光响应性能。而将金属特性的厚层MnTe作为MoS₂场效应晶体管的接触电极，显著提高了器件性能，如载流子迁移率可从12.76 cm²∙V⁻¹∙s⁻¹ (Au接触)提升到47.34 cm²∙V⁻¹∙s⁻¹ (MnTe接触)。