Ab Initio Computational Details With Facile High-Temperature Synthesis of Pure and Alloyed CsPbI3 With Inherent Stability Analysis for Optoelectronic Applications

In this article, wee have performed a density functional theory-based computational experiment to gain insight into stability issues in host CsPbI
₃
and attempted doping Mn as a dopant element to stabilize its phase. The obtained results throw light on various useful parameters like lattice structure, electronic band, absorption coefficient, and photoluminescence (PL). The optimized lattice parameter values of parent CsPbI
₃
quantum dots (QDs) show a diminution in its value after introducing Mn on the Pb site in the crystal structure from 6.28 to 6.15 Å. This result is following the values of the lattice parameter obtained from experimentally observed X-ray diffraction (XRD) plot (6.25 to 6.15 Å) and high-resolution transmission electron microscopy (6.29 to 6.13 Å). Incorporation of Mn in parent CsPbI
₃
QDs leads to phase stability, which can be seen in XRD, PL, and absorption spectra. The PL intensities can be preserved up to 30% and 80% in the case of host and Mn-alloyed CsPbI
₃
QDs, respectively. The phase of host CsPbI
₃
can be preserved up to five days, while the phase of Mn-alloyed CsPbI
₃
QDs can be maintained up to 28 days, which can be seen in XRD plots. In addition, an increment in bandgap from 1.426 to 1.513 eV can be observed after Mn performing alloying in CsPbI
₃
QDs from the theoretically calculated band structure plot, which can be further validated with the obtained bandgap values from the Tauc plot (1.76 to 1.81 eV) extracted using UV-visible spectrum.