Ruddlesden–Popper 2D Chiral Perovskite‐Based Solar Cells

Abstract

In this work, 2D chiral perovskite is demonstrated, where the barrier molecules are the two enantiomers (R)‐(+)‐α‐Methylbenzylamine (R‐MBA) and (S)‐(‐)‐α‐Methylbenzylamine (S‐MBA). The chirality is manifested at high χ values and pure 2D structure measured by circular dichroism (CD) (where the perovskite general formula is ABX3 χ (S/R‐MBA)2PbI4, χ is the ratio of the barrier molecule to the small cation (A+)). The anisotropy factor (gabs) decreased by an order of magnitude when decreasing the χ value achieving 0.0062 for pure 2D. Ab initio many‐body perturbation theory successfully describes the bandgaps, absorbance, and CD measurements. For the first time, these quasi‐2D chiral perovskites are integrated into the solar cell. Using circular polarization (CP) and cutoff filter, the chirality effect from the solar cells photovoltaic response is able to be distinguished. It is revealed that at high χ values, the chirality affects the current density of the solar cell more than at low χ values while the open‐circuit voltage didn't change. These chiral 2D perovskite are new class of materials which open the way for polarized hybrid perovskite.

Tuning Phase Purity in Chiral 2D Perovskites

“…Depending on the film preparation conditions and the choice of organic cation, it is possible to observe X-ray diffraction (XRD) features corresponding to 1D polymeric face-sharing leadhalide octahedra chains (Figure 1c) with the chemical formula A'BX 3 . [26,27,[50][51][52][53] However, the appearance of this phase is not always discussed. Understanding the phase inhomogeneity is a key point since the 1D phase can impact charge-carrier-dependent properties due to the higher content of insulating organic cations in the 1D phase and the higher lattice separation between the inorganic sheets, which potentially hinders charge transport.…”

“…Furthermore, examining the chiral 2D perovskite literature, one can identify many differences in the XRD features of the racemic mixture compared to the pure enantiomers (R and S), which includes the appearance of new diffraction peaks, changes in the relative peak intensities, and the values of full width at half maximum (FWHM). [5,26,28,34,50,54] Therefore, it is clear that the spatial orientation of the organic molecule can influence the products obtained and/or the orientation/purity of the phases. However, up to date, and to the best of our knowledge, the influence of the organic cation orientation in the phase purity of low-dimensional perovskite has not been explored.…”

Circularly Polarized Light Emission from Nonchiral Perovskites Incorporated into Nanoporous Cholesteric Polymer Templates

“…Therefore, the introduction of chirality into nonchiral perovskites can address this limitation and expand their potential applications. In addition to the useful physicochemical properties of halide perovskites, chiral halide perovskites exhibit chirality-related properties, which positions them as pivotal materials for high-performing electronic, optical, and spintronic devices. − …”

“…25,38,47 In particular, 2D and quasi-2D chiral HOIPs synthesized via direct synthesis have been extensively studied, where diverse chiral organic molecules acting as potential barriers between inorganic layers are incorporated into the perovskite structures. 25,29,50 The optical and electrical properties of these chiral HOIPs are easily tunable by adjusting the number of layers and chemical composition, thereby enhancing their versatility for various applications. However, current fabrication methods mostly rely on complex chemical synthesis routes.…”

“…Recent research on chiral halide perovskites has primarily concentrated on HOIPs, ,,,,,,− due to their highly customizable chemical compositions and dimensionalities. These characteristics allow for the exploration of various kinds of chiral perovskites, offering diverse avenues for development. ,, In particular, 2D and quasi-2D chiral HOIPs synthesized via direct synthesis have been extensively studied, where diverse chiral organic molecules acting as potential barriers between inorganic layers are incorporated into the perovskite structures. ,, The optical and electrical properties of these chiral HOIPs are easily tunable by adjusting the number of layers and chemical composition, thereby enhancing their versatility for various applications. However, current fabrication methods mostly rely on complex chemical synthesis routes.…”