Experimental and computational DFT, drift-diffusion studies of cobalt-based hybrid perovskite crystals as absorbers in perovskite solar cells

Abstract

The optimised designs of dimethyl ammonium cobalt formate-based perovskite crystals [(CH₃)₂NH₂]Co(HCOO)₃ were experimentally synthesized and computationally utilized as absorbers for perovskite solar cells (PSCs). Crystals were grown using solvothermal synthesis. Additive materials (Fe, Ni) are responsible for the growth and suppression of crystals in the micrometre range. Temperature and pressure were altered to obtain optimum growth conditions. Grown crystals were characterized by spectroscopy (XRD, FT-IR, UV-Vis) and optical microscopy. Combined density functional theory (DFT) and drift-diffusion modelling frameworks were simulated. These simulators were used to examine various perovskite absorbers for solar-cell configurations. Field calculations were used to examine the structural stability, band structure, and electronic contribution of the constituent elements in [(CH₃)₂NH₂]Co_1−nM_n(HCOO)₃ (M = Fe, Ni and n = 0, 0.1) as absorber material. Conventional TiO₂ and spiro-OMeTAD were used as the electron-transport layer and hole-transport layer, respectively, and Pt was used as a back contact. Comprehensive analysis of the effects of several parameters (layer thickness, series and shunt resistances, temperature, generation-recombination rates, current–voltage density, quantum efficiency) was carried out using simulation. Our proposed strategy may pave the way for further design of new absorber materials for PSCs.