Methodologies for >30% Efficient Perovskite Solar Cells via Enhancement of Voltage and Fill Factor

Abstract

To further improve power conversion efficiency (PCE) toward ShockleyÀQueisser limit efficiency approaching 32% for a single-junction perovskite solar cell (PSC) based on a lead halide perovskite with a bandgap of about 1.45 eV, it is important to improve the open-circuit voltage and fill factor (FF) significantly without sacrificing short-circuit current density. Herein, the advancements of the formamidinium-rich PSCs with PCEs exceeding 23% from the viewpoints of composition engineering, solvent engineering, additive engineering, and interface engineering are summarized and discussed. Based on the lessons, the possible strategies, methods, and research directions are proposed to further improve voltage and FF for ideal PCEs.

Modulating Chemical Interaction to Realize Bottom‐Up Defect Passivation for Efficient and Stable Perovskite Solar Cells

“…However, continuous efforts should be made to further increase PCE in order to narrow the gap between practical PCE and theoretical PCE because the theoretical Shockley–Queisser limit efficiency of single‐junction PSC is exceeding 32%. [ 4 ] The nonradiative recombination caused by the defects within perovskite and charge transport layers as well as at interface is a barrier to the further improvement of efficiency and stability. [ 5 ] Therefore, minimizing trap‐assisted nonradiative recombination is needed to further device performance toward the practical deployment.…”

A synergistic co-passivation strategy for high-performance perovskite solar cells with large open circuit voltage

“…[7][8][9] However, there is still a certain range of improvement relative to the theoretical Shockley-Queisser limit (B33%). 10,11 One of the most restrictive factors is the unavoidable result in numerous shallow level defects (such as the iodide and monovalent cation vacancy (V I , V MA , V FA , etc.)) and deep level defects (such as monovalent and iodide antisite substitutions (MA I + , FA I + , I MA + , I FA + , etc.)…”

Stabilizing Perovskite Precursor by Synergy of Functional Groups for NiOx‐Based Inverted Solar Cells with 23.5 % Efficiency

“…In addition to the oxidation of I − ions, the degradation of perovskite precursor solution containing formamidinium (FA + ) and methylammonium (MA + ) can also be triggered by the deprotonation of organic ammonium cation and following addition‐elimination reaction [18] . FAPbI 3 possesses the narrowest band gap of 1.45–1.52 eV among all known lead‐based metal halide perovskites and has the greatest potential in achieving practical efficiency approaching Shockley–Queisser limit efficiency [22] . Due to the slightly overlarge tolerance factor resulting from the overlarge ionic radius of FA + cation, however, black phase ( α ‐phase) FAPbI 3 easily transforms into yellow phase ( δ ‐phase) [22] .…”