Ga2O3 has emerged as a promising material for deep-ultraviolet (DUV) photodetectors owing to its ultrawide bandgap, intrinsic solar-blind response, low dark current, and high breakdown electric field, making it highly suitable for high-sensitivity DUV sensing applications. However, despite these advantages, several challenges remain in Ga2O3-based DUV photodetectors, including limited carrier transport efficiency, defect-related trap states, and the need for simplified and scalable fabrication routes for doped conductive films. However, the relatively low electron mobility and limited intrinsic carrier transport capability of pristine Ga2O3 restrict further improvements in device performance. To address these limitations, impurity doping has been recognized as an effective strategy to modulate the electrical properties and enhance carrier transport in Ga2O3-based devices. In this work, NiO-doped Ga2O3 films were developed and systematically investigated for application in DUV photodetectors. NiO was introduced as a functional dopant with a fixed atomic ratio of Ga:Ni = 100:12 (12 at%), and NiO-doped Ga2O3 films were deposited using an electron-beam evaporation technique. This approach aims to provide a simplified fabrication pathway while simultaneously improving electrical transport properties without compromising the intrinsic solar-blind characteristics of Ga2O3. The structural, optical, and electrical properties of the doped films were characterized to evaluate the effects of NiO incorporation on material quality and carrier transport behavior. The results demonstrate that NiO doping effectively modifies the electronic characteristics of Ga2O3 while preserving its ultrawide bandgap and solar-blind detection capability. The fabricated photodetectors exhibit reduced dark current and enhanced photoresponse under DUV illumination. Although the present study demonstrates improved photoresponse and stable device performance, further optimization of dopant concentration, defect control, and long-term operational stability remains necessary to fully realize the potential of NiO-doped Ga2O3 for practical large-scale DUV sensing applications. These findings indicate that NiO-doped Ga2O3 films are a promising material platform for high-performance DUV photodetectors and provide valuable insights into the dopant-assisted performance optimization of ultrawide-bandgap oxide semiconductors.