This paper reports the epitaxial growth of Ga₂O₃/nitride thin film heterostructures using a nitrogen-oxide double chamber interconnected metal organic chemical vapor deposition (MOCVD) technique, achieving high-performance ultraviolet photodetector devices. The crystallization quality and surface morphology of the thin films were characterized using X-ray diffraction and atomic force microscopy for different substrates and buffer layer materials. Additionally, the ultraviolet photodetection performance of both planar and heterojunction Ga₂O₃ devices was studied using a photoelectric testing system. The results show that the introduction of an AlN buffer layer can reduce the lattice mismatch between the thin film and the substrate, effectively improving the crystallization quality of the epitaxial Ga₂O₃ thin films on different substrates. Utilizing the advantages of the double chamber, an AlN buffer layer on sapphire and p-Si (111) substrates was introduced respectively, resulting in β-Ga₂O₃ thin films with a preferred orientation of $（\bar{2}01）$ and high structural quality, significantly enhancing the device performance of heterojunction blind ultraviolet photodetectors. Furthermore, we combined β-Ga₂O₃ with p-type GaN to fabricate a pn heterostructure and investigated the effect of different oxide layer thicknesses on the photodetection performance of the heterojunction. Ultimately, high-performance ultraviolet photodetector devices based on Ga₂O₃ were achieved.