Stable and Efficient 3D-2D Perovskite-Perovskite Planar Heterojunction Solar Cell without Organic Hole Transport Layer

Abstract

The expensive and unstable organic hole transport layer (HTL) is one of the crucial problems that hampers the wide application of perovskite solar cells.Here, an MAPbI 3 -(BA) 2 (MA) nÀ1 Pb n I 3n+1 3D-2D perovskite-perovskite planar heterojunction (PPPH) through a facile BAI and MAPbI 3 interfacial ion exchange process was conducted. A graded band structure was formed for efficient charge separation, and the conductivity of the 2D perovskite can be tuned by extrinsic FA incorporation, which provides effective conducting channels for holes, making the modified 2D perovskite layer a promising and stable HTL. Optimized solar cells based on 3D-2D PPPH showed a champion power conversion efficiency (PCE) of 13.15% initially and 16.13% after thermal aging, and could maintain 71% output for 50 days under 65% humidity, and 74% for 30 days under 85 C, without encapsulation. This work points to realize low cost and ambient compatible PPPH solar cells with high PCE and robust stability.

Realizing Reduced Imperfections via Quantum Dots Interdiffusion in High Efficiency Perovskite Solar Cells

“…Presence of low‐dimensional perovskite is known to be beneficial for the reduction of ionic migration and improvement of OIHP solar cells’ ambient stability. [ 55–57 ] The formation of low dimensional phase further reiterates the occurrence of solid‐state interdiffusion in the QD‐modified OIHP films. A similar shift in (001) peak position is observed on modifying MAPbI 3 with QDs‐Cs5 (Figure S4b, Supporting Information), consistent with increased lattice constant a result of elemental substitution.…”

Fast and interpretable classification of small X-ray diffraction datasets using data augmentation and deep neural networks

“…33 In perovskites and perovskites-inspired materials, for instance, 3D crystalline structures have been shown to have good carrier-transport properties for solar cells and LED applications, 33,34 while 3D-2D mixtures have been found to have greater stability in lead halide perovskites than pure-phase 3D crystals. 35 With further detail, the space-group number describes the standardized symmetry group of a configuration in space, classifying crystal symmetries into 230 groups. Identifying the space-group number of a sample provides crystal information beyond dimensionality, including atomic bonding angles and relative distances, which are believed to be of importance for predicting material properties 36 .…”

Interlayer Cross‐Linked 2D Perovskite Solar Cell with Uniform Phase Distribution and Increased Exciton Coupling

“…But to date, the insulating ligands, i.e., BA ( n ‐butylammonium) and PEA (phenethylammonium), are mostly investigated by researchers to form Ruddelsden–Popper (RP) phase 2D perovskites . RP phase 2D perovskites are attractive for several reasons: First, the solution‐processed 2D perovskite film exhibits the unique multicomponent quantum wells (MQW) structure that could naturally confine excitons, showing their enormous potential in light emitting diode (LED) applications . Second, the orientation of 2D slices could be altered perpendicular to the substrates to facilitate charge collection efficiency with many methods, such as hot‐casting NH 4 SCN or NH 4 Cl additive assisting .…”