Structural Dimensionality Dependence of the Band Gap in A_n+1B_nX_3n+1 Ruddlesden–Popper Perovskites: A Global Picture

Abstract

Dimensionality engineering in A n+1B n X3n+1 Ruddlesden–Popper (RP) perovskites has recently emerged as a promising tool for tuning the band gap to improve optoelectronic properties. However, the evolution of the band gap is dependent on the material; distinguishing the effects of different factors is urgently needed to guide the rational design of high-performance materials. Through first-principles calculations, we perform a systematic investigation of RP oxide, chalcogenide, and halide perovskites. The results reveal that in addition to the confinement effect and the change in octahedral rotation motions and/or amplitudes, interfacial rumpling and a change in the A-site cation coordination number also determine the evolution of the band gap. More importantly, we emphasize that the evolution of the band gap in RP perovskites is not dependent on the material family. Instead, the B-site frontier orbital type (s, p, and d) and bandwidth, A-site cation, interfacial rumpling, and structural distortions simultaneously determine the evolution of the band gap. These insights enable a complete and deeper understanding of various experimental observations.

Impact of light illumination on the surface structure of two-dimensional Ruddlesden–Popper perovskite in the fabrication process

“…Recently, two-dimensional Ruddlesden-Popper (2DRP) perovskites have been intensively studied to overcome the environmental instability of their three-dimensional (3D) counterparts [1][2][3][4][5]. They have exhibited outstanding potential for use in optoelectronic devices, such as solar cells and light-emitting diodes, because they offer beneficial properties that extend beyond excellent stability, such as high photoluminescence (PL) quantum yields [6][7][8], structural versatilities [9,10], and tunable band gaps [11][12][13]. The 2DRP perovskite has a unique crystal structure, in which bulky organic cation spacers are intercalated between each octahedron sheet consisting of regular 3D perovskite.…”

Displacive phase transitions in infinite-layer nickelates from first- and second-principles calculations

“…In addition, AFD motions can facilitate the design of polar metal [11][12][13] and magnetically induced multiferroics [14][15][16][17][18][19][20]. From an electronic point of view, AFD motions have been widely exploited as practical strategies to optimize properties such as band gap [21][22][23][24][25], metal-insulator transition of RNiO 3 (where R denotes rare-earth) and RMnO 3 [26][27][28][29][30][31][32], and even the superconductivity of cuprates [33][34][35][36]. From the viewpoint of magnetic properties, AFD motions have been revealed to be of direct relevance to magnetic interactions [37][38][39], Néel/Curie temperature [40][41][42][43][44], and magnetic order [45][46][47][48].…”