Challenges of lead leakage in perovskite solar cells

Abstract

Solar energy is a promising energy source to resolve the expanded demand for energy for global development. In recent years, perovskite solar cells (PSCs) have shown dramatic improvement from device...

Atomistic Description of the Impact of Spacer Selection on Two-Dimensional (2D) Perovskites: A Case Study of 2D Ruddlesden–Popper CsPbI3 Analogues

“…Bulk perovskites have a chemical formula of ABX 3 , for which an A:B charge ratio of 1:2 is most common, where A is a monovalent organic or inorganic cation, B is Pb, Sn, or Ge, and X is a halogen anion. However, the primary drawback of bulk perovskites for solar energy applications remains their poor long-term stability, which leads to the required maintenance or disposal of damaged cells, and the leakage of building components into the environment. − The latter is particularly problematic for the best performing perovskites that have Pb as the B cation, and extensive effort is currently being dedicated to mitigating this lead leakage. − To improve the stability of ABX 3 perovskites while maintaining PV performance, mixed metal double perovskites and two-dimensional perovskites (2DPKs) have emerged as primary candidates for the next generation of highly efficient solar energy-harvesting materials. − Two-dimensional (2D) analogues of bulk perovskites stand out as a particularly promising platform for increasing both the stability and the tunability of perovskite solar cells. − 2D materials more broadly are unrivaled in their ability to realize highly tunable electronic structures, variable layered arrangements, and confinement effects associated with an electronic decoupling of adjacent inorganic layers. − 2DPKs come in three primary phases: (1) the 2D Ruddlesden–Popper (2DRP) phase, where adjacent layers exhibit a half-unit cell shift along both in-plane directions, (2) the Dion Jacobson phase, where adjacent layers are stacked directly atop one another, and (3) the alternating cation phase, where adjacent layers exhibit a half-unit cell shift along one in-plane direction …”

Translucent perovskite photovoltaics for building integration

“…In consequence of regulatory requirements, strategies to reduce lead leakage of perovskite-based PV devices become highly relevant for systems in close proximity to humans like BIPV in particular, but can affect device performance and appearance. 63 Developed solutions can be categorized in physical barriers that prevent invasion or leakage of water and oxygen, and chemisorption layers that chemically absorb and bind free-state lead. For both categories, solutions as external coating ( e.g.…”

A Semitransparent Silver–Bismuth Iodide Solar Cell with Voc above 0.8 V for Indoor Photovoltaics

“…Organic–inorganic lead halide perovskites (OIHPs) are some of the most promising materials for photovoltaics (PVs). Over recent years, by making the best utilization of their properties such as large absorption coefficients, small exciton binding energies, and high carrier mobilities, the power conversion efficiency (PCE) of OIHP solar cells has been increased up to 25.8%, comparable with that of silicon-based solar cells. , However, the environmental toxicity of lead (Pb) remains a discouraging factor for the commercialization of perovskite solar cells. , To overcome this problem, a great amount of effort has been and is being put into Pb-free perovskites and perovskite-like compounds. For example, the substitution of Pb with a divalent metal, like tin (Sn 2+ ) or germanium (Ge 2+ ), has produced impressive results, but the rapid oxidation of Sn 2+ to Sn 4+ or Ge 2+ to Ge 4+ makes them unstable, with intensive efforts needed to stabilize the device. − Heterovalent substitution is another approach, where a trivalent cation such as Bi 3+ with the same n s 2 electron configuration as Pb 2+ is used in combination with a monovalent cation such as Ag + to compensate for the two Pb 2+ ions in the structure, resulting in double perovskites, A 2 M′M″X 6 (Cs 2 AgBiBr 6 , Cs 2 AgInCl 6 , Cs 2 AgSbCl 6 , etc.…”