Unveiling the Optoelectronic Features and Physical Stability of Novel Cs2HgPdI6: Computational Insights

In recent years, researchers have been devoted to search for novel stable halide perovskite materials with outstanding photovoltaic performance. Herein, through density functional theory (DFT) calculations, we uncover for the first time the crystal stability, structural parameters, optoelectronic features, and photovolatic performance of Cs2HgPdI6. The Jahn-Teller-distorted Cs2HgPdI6 is detected by its structural feature. The stability of novel Cs2HgPdI6 is completely ensured by means of the DFT calculations. Accurate electronic structure calculations show that Cs2HgPdI6 exhibits an appropriate fundamental gap (1.278 eV). This band gap is mainly determined by the interaction between the I-5p and Pd-4d orbitals. Additionally, Cs2HgPdI6 has good carrier mobility and an ultra-low exciton binding energy. Meanwhile, it also exhibits relatively weak anisotropic optical properties and strong visible-light absorption. The large theoretical conversion efficiency of 31.7 % is illustrated for Cs2HgPdI6. Overall, our research highlights the great potential of this novel compound for photovoltaic applications.