Effective Phase‐Alignment for 2D Halide Perovskites Incorporating Symmetric Diammonium Ion for Photovoltaics

Abstract

New structural type of 2D AA′ n−1 M n X 3n+1 type halide perovskites stabilized by symmetric diammonium cations has attracted research attention recently due to the short interlayer distance and better charge-transport for high-performance solar cells (PSCs). However, the distribution control of quantum wells (QWs) and its influence on optoelectronic properties are largely underexplored. Here effective phase-alignment is reported through dynamical control of film formation to improve charge transfer between quantum wells (QWs) for 2D perovskite (BDA)(MA) n-1 Pb n I 3n+1 (BDA = 1,4-butanediamine, 〈n〉 = 4) film. The in situ optical spectra reveal a significantly prolonged crystallization window during the perovskite deposition via additive strategy. It is found that finer thickness gradient by n values in the direction orthogonal to the substrate leads to more efficient charge transport between QWs and suppressed charge recombination in the additive-treated film. As a result, a power conversion efficiency of 14.4% is achieved, which is not only 21% higher than the control one without additive treatment, but also one of the high efficiencies of the low-n (n ≤ 4) AA′ n−1 M n X 3n+1 PSCs. Furthermore, the bare device retains 92% of its initial PCE without any encapsulation after ambient exposure for 1200 h.

DFT study of X‐site ion substitution doping of Cs 2 PtX 6 on its structural and electronic properties

“…The inorganic–organic hybrid perovskites solar cells (HPSCs), which are expected to generate renewable resources and resolve global energy problems because of their favorable properties including low cost, superior absorption coefficient, 1,2 appropriate bandgaps, and easy fabrication process 3,4 . The power conversion efficiencies achieved by these materials have steadily improved and currently reach 25.7% 5 .…”

Layered 2D Halide Perovskites beyond the Ruddlesden–Popper Phase: Tailored Interlayer Chemistries for High‐Performance Solar Cells

“…MACl is also found to be effective. Zhang et al [50] . showed that MACl can slow down the crystallization of DJ perovskite (BDA)(MA) 3 Pb 4 I 13 (Figure 5 b) and induce its film formation with much lower trap‐state densities, which accordingly leads to enhanced PCEs and environmental stability of the resultant PSCs.…”

Beyond the Phase Segregation: Probing the Irreversible Phase Reconstruction of Mixed‐Halide Perovskites

“…in 2009, [ 1 ] perovskite solar cells (PSCs) have rapidly developed in the next decade, achieving a world record power conversion efficiency (PCE) of 25.5%. [ 9–13 ] Besides photovoltaics, perovskites have also demonstrated promising potential for the applications of light‐emitting devices, lasers, photodetectors, and high‐energy radiation detection. [ 14–17 ]…”

“…[6][7][8] Since the first report of using MAPbX 3 as the light-harvesting material for photovoltaics by Miyasaka et al in 2009, [1] perovskite solar cells (PSCs) have rapidly developed in the next decade, achieving a world record power conversion efficiency (PCE) of 25.5%. [9][10][11][12][13] Besides photovoltaics, perovskites have also demonstrated promising potential for the applications of light-emitting devices, lasers, photodetectors, and high-energy radiation detection. [14][15][16][17] While the research interest on perovskite-based optoelectronics is initiated by MAPbI 3 , the state-of-the-art devices usually employ binary/ternary cation and double-halide perovskites (e.g., Cs 1−y−z FA y MA z Pb(I 1−x Br x ) 3 ) as the light-absorbing layer.…”