The overall goal of this project is to successfully prepare diamond films with controlled color centers in microgravity, suitable for various terrestrial quantum technologies being pursued for extensive commercial applications in quantum sensing, quantum cryptography, quantum computing and quantum information processing. The major technical issues currently include realization of distinguishable emission, improving photon collection efficiency and other practical issues, all related to material quality, control of color centers (their location and distribution) and manufacturing technologies. There is an opportunity to address the above issues and develop a clear understanding of controlling mechanisms in the growth and incorporation of color centers through microgravity experiments that can eventually lead to manufacturing facilities in space. We aim to conduct microgravity experimental studies in four years from the start of Phase I. An existing plasma based printer, originally developed as an alternative to inkjet and aerosol jet printing and successfully commercialized, will be adapted into a plasma reactor in the proposed project. Availability of this hardware significantly reduces the risk in the proposed effort. The Phase I effort will demonstrate the capability of growing diamond using the plasma printer operated in a plasma enhanced chemical vapor deposition mode and methane-hydrogen precursors. Diamond films will also be printed using diamond nanopowder ink. Silicon color centers will be incorporated onto the diamond films from both cases above simply by injecting silicon ink into the plasma printer. In addition to these preliminary demonstrations, the Phase I effort will prepare a clear plan for the microgravity preparation of diamond films with controlled color centers, assess modifications necessary for the plasma printer for microgravity operation, and conduct design and process development studies for successful microgravity experiments.

This proposal is in line with the goals of the NASA INSPA program. As with past successful microgravity crystal growth and thin film growth studies, the present project seeks to gain better understanding of diamond thin film growth characteristics and color centers through experiments in controlled microgravity environment. The knowledge gained has the potential to eventually lead to manufacturing facilities in space to produce diamond thin films with controlled color centers needed in all quantum technologies.

Potential applications are quantum technologies such as quantum sensing, quantum cryptography, quantum computing and quantum information processing. These applications are not only vital for national security but also for future economy. Countries that control the intellectual property and manufacturing would gain huge economic benefits. This is also in line with the CHIPS Act of 2022.