This PhD position is offered by AIT Austrian Institute of Technology, Austria’s largest research and technology organisation for applied research. AIT plays a central role in addressing major global challenges such as climate change and digitalisation, combining scientific excellence with strong industrial and societal impact. The position is based at AIT’s Center for Energy in Vienna, which develops sustainable and future-oriented solutions for cities and the built environment, public energy supply, and industrial energy systems. The PhD project focuses on innovative cooling solutions for high-power data centers and high-performance electronic systems, a rapidly growing challenge driven by increasing power densities in modern CPUs and GPUs used in HPC and AI applications. While liquid cooling technologies such as Direct-to-Chip (D2C) outperform conventional air cooling, they still rely on additional air-based systems. This project goes a step further by investigating immersion cooling, with a strong emphasis on two-phase immersion cooling (2PIC), where a fluid boils directly on the chip surface to achieve highly efficient heat removal. A central innovation of the PhD is the integration of 2PIC with heat pump systems to upgrade waste heat and reuse it as a valuable energy resource. This approach directly contributes to the development of sustainable, energy-efficient data centers and supports broader decarbonisation goals. The research combines system modelling and dynamic simulations, experimental investigations, techno-economic and feasibility analyses, and work on standards and system integration. Close collaboration with industrial and academic partners ensures strong practical relevance and impact. Applicants should hold (or be close to completing) a Master’s degree in Thermal Engineering, Sustainable Energy Systems, Mechanical or Process Engineering, Electrical Engineering, Physics, or a related field. Skills in modelling and simulation, programming (Python), and experimental work are essential. Very good English is required; German is an advantage. The PhD runs for 3 years, ideally starting 1 April 2026, with enrollment at TU Wien and joint supervision by TU Wien and AIT. The position offers €2,786.10 gross per month (14× per year) for 30 hours/week, flexible working conditions, and access to AIT’s international PhD community of around 150 doctoral researchers.