Strain coupling and Jahn–Teller effect in efficient and stable sky-blue germanium–lead perovskites

Abstract

Substitution of lead (Pb) with environmentally friendly germanium (Ge) is a very important and promising method to reduce the toxicity as well as improve the efficiency and stability of the...

Intrinsic stability of perovskite materials and their operational stability in light-emitting diodes

“…Recently, Rao et al 6 reported that replacing Pb 2+ with 30% Ge 2+ in phenylethyl ammonium chloride (PEACl) blended CsPbBr 3 improves the stability and emission efficiency. This is due to reduced Jahn–Teller distortion and the increased tolerance factor compared to the Pb 2+ -based perovskite.…”

Theoretical investigation of octahedral tilting and bandgap non‐linearity in monolayer Ruddlesden‐Popper A 2 Pb 1‐x Ge x I 4 perovskites

“…Fu et al 50 relaxed the Goldschmidt tolerance factor requirement for 2D‐perovskites allowing various large organic cations to occupy the cuboctahedral cavity of the perovskite cage in 2D‐perovskites. Ruddlesden‐Popper (RP) phase 23,46,48,51,52 as an important class of 2D‐perovskites has monoamine R‐NH 3 cations as PEA + 53 . These bulky hydrophobic organic spacer cations fill the voids between inorganic sheets of metal‐halide octahedral cages (BX 6 ) 4− , thus could be a promising solution to address the stability issue.…”

“…The resulting materials were found highly luminescent and suitable for optoelectronic devices with photoluminescence quantum efficiencies of up to 71%. Ge inclusion has been proved a very promising method to reduce lead toxicity and improve the efficiency and stability of perovskite films for practical applications in light‐emitting diodes (LEDs) and solar cells 53 . As Ge‐based perovskites, photovoltaic cells are numerically modelled to match better with the energy band of the selected charge transporting layer 55 .…”

“…Ruddlesden-Popper (RP) phase 23,46,48,51,52 as an important class of 2Dperovskites has monoamine R-NH 3 cations as PEA + . 53 These bulky hydrophobic organic spacer cations fill the voids between inorganic sheets of metal-halide octahedral cages (BX 6 ) 4À , thus could be a promising solution to address the stability issue. Recently, Yang et al 54 studied the Pb-Ge based perovskites formulated as CsPb 0.9 Ge 0.1 Br 3 (3D), PEA 2 Pb 0.9 Ge 0.1 Br 4 (2D), and PEA 2 Cs nÀ1 (Pb 1Àx Ge x ) n Br 3n+1 (quasi-2D).…”

“…Ge inclusion has been proved a very promising method to reduce lead toxicity and improve the efficiency and stability of perovskite films for practical applications in light-emitting diodes (LEDs) and solar cells. 53 As Ge-based perovskites, photovoltaic cells are numerically modelled to match better with the energy band of the selected charge transporting layer. 55 Numerous theoretically investigated lead-free low-dimensional perovskites are found to have unique structure-property characteristics, which endow them with a combination of optoelectronic efficiency and versatile functionality, offering state-of-the-art employment in the optoelectronic devices.…”