Highly Efficient Ruddlesden–Popper Halide Perovskite PA2MA4Pb5I16 Solar Cells
Journal article, 2018
Two-dimensional (2D) Ruddlesden-Popper (RP) organic-inorganic perovskites have emerged as promising candidates for solar cells with technologically relevant stability. Herein, a new RP perovskite, the fifth member («n» = 5) of the (CH3(CH2)2NH3)2(CH3NH3)n-1PbnI3n+1 family (abbreviated as PA2MA4Pb5I16), was synthesized and systematically investigated in terms of photovoltaic application. The obtained pure PA2MA4Pb5I16 crystal exhibits a direct band gap of Eg = 1.85 eV. Systematic analysis on the solid film highlights the key role of the precursor-solvent interaction in the quantum well orientation, phase purity, grain size, surface quality, and optoelectronic properties, which can be well-tuned with addition of dimethyl sulfoxide (DMSO) into the N,N-dimethylformamide (DMF) precursor solution. These findings present opportunities for designing a high-quality RP film with well-controlled quantum well orientation, micrometer-sized grains, and optoelectronic properties. As a result, we achieved power conversion efficiency (PCE) up to 10.41%.