In this work, CuAlO₂ films were prepared on 4H–SiC (0001) using the sol-gel method. The surface morphology, structure and optical characteristics of the prepared films were studied. A homogeneous distribution of fine rhombohedral crystal structural grains is observed on the 4H–SiC substrate using scanning electron microscope (SEM). The film was confirmed to consist predominantly of delafossite CuAlO₂ phase and impurity spinel CuAl₂O₄ phase via X-ray diffraction (XRD). The direct optical bandgap estimated from the measured transmittance spectra is approximately 3.85eV, while the indirect bandgap is 1.78 eV. Four emission peaks are observed in the photoluminescence (PL) spectra measured at room temperature. The emission peaks around 360 nm and 380 nm are the near band edge emission (NBE) of the prepared CuAlO₂ films and the 4H–SiC substrate, respectively. The other two emission peaks around 410 nm and 470 nm arises from defects of Cu-vacancy. The fabricated p-CuAlO₂/n-4H–SiC heterojunction diode exhibits typical rectification. Additionally, the turn-on voltage and rectification ratio at ± 3 V are determined to be 1.6 V and 1.26 × 10³, respectively. A further 7.15 × 10⁹ times increase of the hole injection capacity could be acquired potentially through an analysis of the energy band structure, which suggests that high injection capacity SiC bipolar devices could be feasibly achieved by utilizing CuAlO₂ as the p + emitter.

在这项工作中，使用溶胶-凝胶法在4H-SiC（0001）上制备了CuAlO ₂膜。研究了所制备薄膜的表面形貌，结构和光学特性。使用扫描电子显微镜（SEM）在4H–SiC衬底上观察到细小的菱面体晶体结构晶粒的均匀分布。确认该膜主要由铜铁矿CuAlO ₂相和杂质尖晶石CuAl ₂ O _4组成通过X射线衍射（XRD）扫描相。根据测得的透射光谱估计的直接光学带隙约为3.85eV，而间接带隙为1.78eV。在室温下测量的光致发光（PL）光谱中观察到四个发射峰。在360 nm和380 nm附近的发射峰分别是所制备的CuAlO ₂薄膜和4H-SiC衬底的近带边缘发射（NBE）。大约410 nm和470 nm处的其他两个发射峰是由Cu空位缺陷引起的。制成的p-CuAlO ₂ / n-4H-SiC异质结二极管表现出典型的整流作用。另外，在±3 V时的导通电压和整流比分别确定为1.6 V和1.26×10 ³。另外7.15×10 ⁹通过对能带结构的分析，可以潜在地获得两倍的空穴注入容量的增加，这表明通过使用CuAlO ₂作为p +发射极可以实现高注入容量的SiC双极器件。