Exploring novel Zr2GeX (X = C, N, F) MAX phases by first-principles approach

In recent years, there has been a surge of interest in the thermodynamically stable nanolaminate ternary carbides/nitrides known as MAX phases. In this first-principles research work, we focus on the MAX phases with a particular emphasis on Zr2GeX (X = C, N, F) compounds. These novel Zr2GeX compounds exhibited considerable values of cohesive energy, demonstrating stability comparable to well-established MAX compounds. Our calculations for the structural parameters of Zr2GeX agree well with the literature, indicating the reliability of our results. The absorption coefficients for ultraviolet (UV) light are approximately 105/cm and 106/cm, respectively, highlighting their significance for energy harvesting devices. Additionally, these metallic compounds demonstrate impressive reflectivity, reflecting over 50% of infrared and visible light. Similarly, they exhibit the highest refraction for infrared light, with a significant decrease in refraction for visible and UV light. Consequently, the transparency of Zr2GeX compounds diminishes, rendering them opaque against UV light and highly likely to absorb most incident UV radiation. Results presented in this paper highlight the potential applications of Zr2GeX MAX phases for optoelectronic devices due to their exceptional electronic and optical properties.