Selective growth of layered perovskites for stable and efficient photovoltaics

Abstract

We achieved improvement in performance and stability of PSCs by growing 2D perovskite layer on top of 3D perovskite films.

High‐Performance Perovskite Solar Cells with Enhanced Environmental Stability Based on a (p‐FC6H4C2H4NH3)2[PbI4] Capping Layer

“…To further confirm the presence of the 2D perovskite layer, we performed photoluminescence (PL) analysis of the pristine 3D, 2D, and 3D-2D perovskites by observing the emission from the frontier surface of perovskite samples under 450 nm light excitation ( Figure 2d). This phenomenon agrees well with the published results [29] and can be attributed to the quantum confinement effect of the in situ formed an ultrathin layer of FPEA 2 PbI 4 . [11] Compared to the two single-phase perovskite film, the FPEAI modified film shows a dual emission behavior with a sharp peak at 502 nm and a relatively weaker peak at 765 nm.…”

“…[18,25,28,29] In our case, the extra fluorine atoms on the phenyl groups should enhance moisture tolerance further as already being proved in the recent report on the change of XRD patterns over time. The modified surface of 3D perovskite features a 2D perovskite capping layer, on top of which the FPEA + ion is presented at the terminal of the crystal with the hydrophobic p-fluorophenyl groups acting as the barrier to prevent the invasion of H 2 O from ambiance to grain boundaries in high humidity environments.…”

“…[24] In a similar report, a 3D-2D (MAPbI 3 -PEA 2 PbI 4 ) graded perovskite film resulted in an overall PCE of 19.89%. [26][27][28][29] Very recently, Lee et al incorporation of PEA 2 PbI 4 into the precursor solution of FAPbI 3 . [26][27][28][29] Very recently, Lee et al incorporation of PEA 2 PbI 4 into the precursor solution of FAPbI 3 .…”

Two-dimensional organic-inorganic hybrid perovskite: from material properties to device applications

“…Other cases are the utilizations of 2D perovskites as modified layers between absorption layer and transport layers for interface passivation [95][96][97]. A layer of (PEI) 2 PbI 4 between PEDOT:PSS and MAPbI 3 acts as a growing template for micron-grain and favours the formation of homogeneous films.…”

“…It is worth mentioning that the PCE showed almost no decline after 4 months in the air if the spiro-OMeTAD layer and Au electrode were prepared right before tested. Furthermore, Cho et al [97] selectively grew 2D perovskite on the surface of Cs 0.1 FA 0.74 MA 0.13 PbI 2.48 Br 0.39 film by treating it with a PEAI isopropanol solution. This thin 2D perovskite layer blocks the transfer of electrons to HTL and reduces the charge recombination owing to energy band offset.…”