Talwar Devki N, Lin Hao-Hsiung, Haraldsen Jason T
Department of Physics, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224-7699, USA.
Department of Physics, Indiana University of Pennsylvania, 975 Oakland Avenue, 56 Weyandt Hall, Indiana, PA 15705-1087, USA.
Nanomaterials (Basel). 2025 Mar 24;15(7):485. doi: 10.3390/nano15070485.
Due to a lower InN bandgap energy Eg~0.7 eV, InxGa1-xN/Sapphire epifilms are considered valuable in the development of low-dimensional heterostructure-based photonic devices. Adjusting the composition x and thickness d in epitaxially grown films has offered many possibilities of light emission across a wide spectral range, from ultraviolet through visible into near-infrared regions. Optical properties have played important roles in making semiconductor materials useful in electro-optic applications. Despite the efforts to grow InxGa1-xN/Sapphire samples, no x- and d-dependent optical studies exist for ultrathin films. Many researchers have used computationally intensive methods to study the electronic band structures Ejk→, and subsequently derive optical properties. By including inter-band transitions at critical points from Ejk→, we have developed a semiempirical approach to comprehend the optical characteristics of InN, GaN and InxGa1-xN. Refractive indices of InxGa1-xN and sapphire substrate are meticulously integrated into a transfer matrix method to simulate d- and x-dependent reflectivity RE and transmission TE spectra of nanostructured InxGa1-xN/Sapphire epifilms. Analyses of RE and TE have offered accurate x-dependent shifts of energy gaps for InxGa1-xN (x = 0.5, 0.7) in excellent agreement with the experimental data.
由于氮化铟（InN）的带隙能量较低，约为0.7电子伏特，因此铟镓氮（InxGa1-xN）/蓝宝石外延膜在基于低维异质结构的光子器件开发中被认为具有重要价值。通过调整外延生长膜中的成分x和厚度d，在从紫外到可见光再到近红外的宽光谱范围内实现发光提供了多种可能性。光学性质在使半导体材料用于电光应用方面发挥了重要作用。尽管人们努力生长铟镓氮/蓝宝石样品，但对于超薄膜尚无关于x和d依赖的光学研究。许多研究人员使用计算密集型方法来研究电子能带结构Ejk→，并随后推导光学性质。通过纳入来自Ejk→临界点的带间跃迁，我们开发了一种半经验方法来理解氮化铟、氮化镓和铟镓氮的光学特性。将铟镓氮和蓝宝石衬底的折射率精心整合到转移矩阵方法中，以模拟纳米结构铟镓氮/蓝宝石外延膜的d和x依赖的反射率RE和透射率TE光谱。对RE和TE的分析给出了铟镓氮（x = 0.5，0.7）的与实验数据高度吻合的准确的x依赖的能隙位移。
