Research Seminar by Dr. Anu Bala on Metal halide perovskites for solar energy and optoelectronic applications

Metal halide perovskites for solar energy and optoelectronic applications

Finding cost effective, abundant, and efficient materials for energy production and storage is one of the biggest challenges of this century. Solar energy is one of the most important sources of energy due to its wide availability and environment friendly nature. In recent years metal halide perovskites have emerged as an important class of semiconductor materials that are easy to fabricate and have desirable properties such as tunable bandgap and high absorption coefficient which enable a broad range of photovoltaic and optoelectronic applications. Since the first embodiment of perovskite solar cells showing a power conversion efficiency of 3.8%, the device performance has been boosted up to a certified 23% within a few years. However, these materials suffer from the problem of stability and low dimensional 2D and 2D-3D perovskites have emerged with good stability.

In this talk, I will focus on these developments and present our work on 2D perovskite materials in an effort to understand the enhanced stability and variation in properties going from bulk to layered systems. Furthermore, rare earth doped semiconductor materials have been studied widely for optoelectronic applications. However, stability of rare earths in different hosts has been a problem. The newly developed halide perovskite materials offer a new paradigm for optoelectronic materials. We have done ab initio calculations for the first time to understand Eu doping in these systems and our results suggest that these perovskites are good hosts for rare earths.

References

1. “Atomic and Electronic Structure of Two-Dimensional Inorganic Halide Perovskites An+1MnX3n+1 (n = 1–6, A = Cs, M = Pb and Sn, and X = Cl, Br, and I) from ab Initio Calculations”, Anu Bala, Arpan Krishna Deb, and Vijay Kumar, J. Phys. Chem. C, 2018, 122 (13), 7464–7473.
2. “Stability of the Eu2+ Dopant in CsPbBr3 Perovskites: A First-Principles Study”, Anu Bala and Vijay Kumar, J. Phys. Chem. C, 2019, 123 (12), 6965–6969
3. “Stabilization of the thinnest layers of tin bromide perovskites by surface ligands: An ab initio study of the structure, electronic, and optical properties”, Anu Bala and Vijay Kumar, manuscript under review.