The effect of multiple ion substitutions on halide ion migration in perovskite solar cells

Abstract

Lead halide perovskites are mixed electronic-ionic conductors. Ionic mobility is related to device stability; the more favourable ion migration is, the sooner material degradation occurs. The highest efficiency perovskite materials,...

Stabilizing α-Phase FAPbI3 Perovskite Induced by an Ordered Solvated Quasi-Crystalline PbI2

“…Strategies to reduce defects have been proposed, such as additive (or solvent) engineering to reduce bulk defects via controlling crystallization, − post-treatment to passivate interfacial defects, , and ion substitution to control ion migration. − It was reported that low-defect density perovskite films with high crystal plane orientation were prepared by introducing the presynthesized, intrinsically highly oriented two-dimensional (2D) Dion–Jacobson perovskite of (BDA)­PbI 4 (BDA = 1,4-butanediamine) into the PbI 2 solution as a seed for three-dimensional (3D) perovskite epitaxial growth, which finally demonstrated a PCE of 23.95% . The 2D Ruddlesden–Popper perovskite of (NpMA) 2 PbI 4 (NpMAI = 1-naphthalenemethylammoniumiodide) was introduced into the PbI 2 solution to modulate crystal growth, which led to a PCE as high as 24.37% .…”

Factors Limiting the Operational Stability of Tin–Lead Perovskite Solar Cells

“…In a similar manner, I – migration in PSCs has raised several concerns related to its negative impact on the performance and stability of devices. Due to a low activation energy (0.3–0.5 eV), the movement of I – upon external stimuli (light, temperature, and bias) is typically assigned as the main contributor to the ion migration in Pb-based perovskites, although many reports suggest that the migration of the A-site cation is not negligible. − During operation (i.e., under illumination and/or bias), accumulation of mobile ions at the contact interfaces screens the built-in potential and/or facilitates the formation of defects, leading to non-radiative recombination . Ion diffusion to transport layers or electrodes can further cause chemical reactions that are harmful to the performance of the device. − To date, the link between ion migration and the stability of TLPSCs remains underexplored; further efforts to unravel the extent of efficiency losses and degradation mediated by ion motion are expected to open up paths toward long-term stability in this class of devices.…”

Bication Thiocyanate Salts for Advanced Performance of Wide-Band Gap Perovskite Solar Cells

“…Because the performance and long-term stability of the tandem solar cells are limited by those of PSCs, it is essential to secure the high quality and stability of the wide-band gap perovskite materials. , Various methods have been proposed to improve the properties of the perovskites: recrystallizing the surface, passivation of surface or grain boundaries, and introducing two-dimensional (2D) mixed phases. − These methods are effective, but they require additional processes and precise control of process conditions.…”