The interest in two-dimensional (2D) material research has increased over the years due to their exceptional mechanical, optical, and electrical properties, with a wide range of applications from nano-electronics to corrosion resistance coatings. More applicable to this work, some 2D materials such as molybdenum disulfide (MoS2), display strong light-matter interactions, highlighting their suitability for applications in optoelectronics and photovoltaics. Device concepts using exfoliated MoS2 have been shown at micron-scale; however, high quality large area films at wafer (>cm2) scale are required to produce next generation devices like flexible, wearable, and ultrathin electronics and photovoltaics. We report on the development of the chemical vapor deposition (CVD) process for wafer scale MoS2 growth, focused on maximizing flake dimensions and film uniformity and the development of a single station setup for correlative spatial mapping of film properties at sub-micron resolution. High-quality MoS2 films are then used to produce high-specific power 2D photovoltaics, which is a promising alternative to conventional solar power conversion systems in space and other flexible, high-specific power applications. Furthermore, the advantage of vertical carrier transport over lateral transport in the device architecture for 2D photovoltaics is presented. This work adds to ongoing efforts focused on improving ultrathin 2D material-based optoelectronics and photovoltaic device efficiency, by synthesis development, contact engineering, and new device architectures. The synthesis and engineering decisions are informed by multiplexed spatial mapping of device properties; device modelling based on the physics of Schottky photovoltaics, optical properties, and work function measurements; innovations in 2D materials-based device fabrication; and advanced analysis of these devices for their implementation in space. The work aims to contribute to the realization of high efficiency, high specific power, 2D materials-based ultrathin photovoltaics.