Crystal and Band-Gap Engineering of One-Dimensional Antimony/Bismuth-Based Organic–Inorganic Hybrids

Abstract

Hybrid halide perovskites are emerging semiconducting materials with a diverse set of remarkable optoelectronic properties. Besides the widely studied lead halide perovskites, Pb-free metal halides such as Bi-and Sb-containing hybrid organic− inorganic materials have shown potential as semiconductors and have been deemed candidates for optoelectronic devices. Here, we report a series of 1D Sb/Bi-based organic−inorganic hybrid alloys: [4ApyH]Sb x Bi 1−x I y Br 4−y , where 4ApyH stands for the 4-aminopyridine cations. These compounds are assembled by edge-sharing octahedral [MX 6 ] units stabilizing 1D chains with organic cations filled in between. The crystallographic data of eight selected complexes show that [4ApyH]Sb x Bi 1−x I y Br 4−y has at least five phases (space group) with the difference metal and halogen content:and [4ApyH]SbBr 4 (100 K)), I2/a ([4ApyH]Sb 0.5 Bi 0.5 I 2 Br 2 and [4ApyH]SbI 2 Br 2 ), and C2/c ([4ApyH]SbI 4 (298 K) and [4ApyH]SbBr 4 (298 K)). Powder X-ray diffraction shows that the phase of the sample changes with a change of the metal and halogen ratios, and the change law accords with Vegard's law. The optical band gaps are heavily affected by the metal and halide contents, ranging from 1.94 eV for [4ApyH]BiI 4 to 2.73 eV for [4ApyH]SbBr 4 . When Sb substitutes for Bi to form an alloy, the band gap increases from 1.94 for [4ApyH]BiI 4 to 1.67 eV for [4ApyH]SbI 4 , from 2.13 eV for [4ApyH]BiI 2 Br 2 to 2.41 eV for [4ApyH]SbI 2 Br 2 , and from 2.55 eV for [4ApyH]BiBr 4 to 2.73 eV for [4ApyH]SbBr 4 . The conductivity of [4ApyH]Sb x Bi 1−x I 4 increased from ∼1.00 × 10 −15 to 2.14 × 10 −8 S cm −1 with an increase of the Sb content. Solution-deposited thin films of the nine complexes show the same (110) orientation, displaying a parallel growth orientation with respect to the substrate. The devices of [4ApyH]Sb 0.8 Bi 0.2 I 4 and [4ApyH]SbI 4 demonstrated stable open-circuit photovoltages of 0.55 and 0.44 V, steady-state short-circuit photocurrent densities of 1.52 and 1.81 mA cm −2 , and light-to-electrical energy conversion efficiencies of 0.29% and 0.30%, respectively.

Small Organic Molecular-Based Hybrid Halides with High Photoluminescence Quenching Temperature

“…The optical band gaps of (C 2 H 8 N) 4 InCl 7 , (C 2 H 8 N) 4 SbCl 7 , and (C 2 H 8 N) 4 SbBr 7 were experimentally determined (indirect band gap) to be 3.80, 3.04, and 2.75 eV, respectively. Despite the band gap differing from that of similarly reported compounds, it was within the fluctuation range, i.e., (C 5 H 5 NCl) 2 InCl 5 (4.05 eV), [N­(C 2 H 5 ) 4 ]­InCl 4 (4.30 eV), (C 8 NH 12 ) 6 InBr 9 ·H 2 O (3.69 eV), C 10 H 28 N 4 In 2 Cl 10 (3.52 eV), (tetraethylammonium) 2 SbCl 5 (3.01 eV), (benzyltriethylammonium) 2 SbCl 5 (3.06 eV), (C 6 H 5 CH 2 NH 3 ) 3 SbBr 6 (2.77 eV), (PPN) 2 SbCl 5 (PPN = bis­(triphenylphosphoranylidene) ammonium cation) (2.70 eV), (4-aminopyridine)­SbBr 4 (2.73 eV), (C 5 H 5 NCl)­Sb 2 Br 10 (2.45 eV), (C 5 H 5 NBr)­Sb 2 Br 10 (2.58 eV), , and (C 5 H 5 NI)­Sb 2 Br 10 (2.43 eV) …”

“…Despite the band gap differing from that of similarly reported compounds, it was within the fluctuation range, i.e., (C 5 H 5 NCl) 2 InCl 5 (4.05 eV), 40 [N(C 2 H 5 ) 4 ]InCl 4 (4.30 eV), 41 (C 8 NH 12 ) 6 InBr 9 •H 2 O (3.69 eV), 18 C 10 H 28 N 4 In 2 Cl 10 (3.52 eV), 42 (tetraethylammonium) 2 SbCl 5 (3.01 eV), 38 ( b e n z y l t r i e t h y l a m m o n i u m ) 2 S b C l 5 ( 3 . 0 6 e V ) , 3 8 (C 6 H 5 CH 2 NH 3 ) 3 SbBr 6 (2.77 eV), 39 (PPN) 2 SbCl 5 (PPN = bis(triphenylphosphoranylidene) ammonium cation) (2.70 eV), 6 (4-aminopyridine)SbBr 4 (2.73 eV), 43 (2.45 eV), 40 (C 5 H 5 NBr)Sb 2 Br 10 (2.58 eV), 40,44 and (C 5 H 5 NI)Sb 2 Br 10 (2.43 eV). 40 For the PL excitation (PLE) and absorption spectrum (Figure S3) of (C 2 H 8 N) 4 InCl 7 , the PLE peaks at 283 and 323 nm correspond to the two sharp absorption peaks at 279 and 333 nm; there is also a small excitation peak at 272 nm, which is related to the exciton absorption peak at 226 nm.…”

Assembling Polyiodides and Iodobismuthates Using a Template Effect of a Cyclic Diammonium Cation and Formation of a Low-Gap Hybrid Iodobismuthate with High Thermal Stability

“…Today, halobismuthates are scrutinized as potential solar light absorbers to replace their efficient but toxic lead congeners. Although the photovoltaic efficiency of Bi-based solar cells has so far reached only 2.1%, the search for new materials is gaining interest and new compounds have been recently synthesized and examined for potential photovoltaic properties [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. In general, halobismuthates fulfill basic requirements for solar light harvesting.…”

Influence of interaction between organic cation and inorganic unit in bi-based hybrid perovskites for photoelectronic properties

“…To compare their crystal structures more clearly, the crystallographic packing diagrams of PDABI and PIDBI viewed along different unit cell directions are shown in Figure 1 , from which can be seen that their BiI 4 - anions all adopted the infinite one-dimensional (1D) chain that has been reported, such as (C 5 H 7 N 2 )BiI 4 [4ApyH]BiI 4 , (C 5 H 6 N)BiI 4 [ 26 , 27 , 28 ]. The 1D cation chains are vertical to [0, 1, 0] plane in PDABI ( Figure 1 a) and [−1, 0, 1] plane in PIDBI ( Figure 1 d), which all composed of edge-share BiI 6 octahedrons.…”