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In order to address the energy challenges of the near future, researchers are currently focused on developing environmentally friendly and energy-efficient phosphors for luminescence devices such as light-emitting diodes (LEDs). When it comes to this topic, older lighting devices such as halogen lamps, LCD backlights, incandescent lamps, and fluorescent lamps can be substituted with advanced next-generation lighting technology created with phosphor-transformed white LEDs. We've conducted a detailed analysis of the structural and optoelectronic characteristics of Cs-based phosphors Cs2MF6 (M = C, Ge, Pb, Si) for potential use in photoluminescence as well as photovoltaic applications such as LEDs. Utilizing the GGA scheme allows for an in-depth analysis of exchange and correlation energy potentials within density functional theory (DFT) first-principles calculations. The calculated structural properties reveals that Cs2PbF6 is the most stable compound among Cs2MF6 (M = C, Ge, Pb, Si) as they possess lowest ground state energy. Direct bandgaps of 1.57, 1.459, 1.481, and 1.59 eV are observed with the presence of intermediate bands for Cs2CF6, Cs2GeF6, Cs2PbF6, and Cs2SiF6, respectively. It is established by analyzing plots that the investigated hexafluorides absorb maximum photons in the UV region. Based on the spectra, it is evident that Cs2MF6 (M = C, Ge, Pb, Si) act as weak reflectors of incident photons in the visible and IR regions. However, around 40% of the incoming photons get reflected at various energies by individual compounds. Thermodynamic characteristics of these hexafluorides reveals that they are thermodynamically stable compounds. [ABSTRACT FROM AUTHOR]

For energy‐efficient and high‐power illumination systems, phosphor materials have attracted huge research attention over the recent decades. Herein, applying the first‐principles method, we investigate and predict the optoelectronic and structural properties of light‐harvesting phosphors Z2SiF6 (Z = K, Li, Na, Rb) as promising candidates for weight‐light‐emitting diodes w‐LEDs. The calculated direct energy band gaps are of order 1.56, 1.461, 1.479, and 1.585 eV for Z2SiF6 (Z = K, Li, Na, Rb), respectively, thus rendering the compound's semiconducting nature suitable for optoelectronic applications. Calculated structural properties show that Rb2SiF6 is the most stable compound among Z2SiF6 (Z = K, Li, Na, Rb). The optical properties in the energy range of 0–14 eV have been investigated using the well‐known (GGA) formulism available in the literature. Studied compounds are active optical materials as the value of their refractive index nω is between 1.0 and 2.0. Based on investigated optical parameters, we can say that Z2SiF6 (Z = K, Li, Na, Rb) are potential candidates for optoelectronic device applications like white LEDs (w‐LEDs). Thermodynamic parameters of Z2SiF6 (Z = K, Li, Na, Rb) are provided to establish the thermodynamic stability of these compounds. [ABSTRACT FROM AUTHOR]