Antimony (V) Complex Halides: Lead‐Free Perovskite‐Like Materials for Hybrid Solar Cells

Abstract

important problem is related to the high acute and chronic toxicity of the lead compounds, which can cause occupational health risks and hinder massive industrial production of raw materials and photovoltaic modules. [3] The need for recycling of the lead-containing photovoltaic panels at the end of their life cycle represents another issue, which has been experienced already in the case of CdTe technology. [4] Thus, the facile photo degradation of complex iodoplumbates and their anticipated negative impact on the environment provide impetus for the development of alternative lead-free light absorbers based on metal halides. [5] Complex tin (II) and germanium (II) halides with the perovskite crystal lattice were thoroughly investigated in effort to develop a new generation of light harvesting materials for solar cells. However, ASnX 3 and AGeX 3 systems (A represents organic cation and X = I, Br) delivered inferior photovoltaic efficiencies, while demonstrating even lower intrinsic stability than the iodoplumbates due to easy disproportionation of M (II) into M (0) and M (IV). [6] Therefore, the most recent efforts have been focused on the exploration of halide complexes of the posttransition group 15 elements such as Bi and Sb. Along with the pioneering reports on BiI 3[7] and A 3 Bi 2 I 9 (A = MA or Cs), [8] a number of other bismuth halides were considered such as BiSI, BiOI, AgBi 2 I 7 , and Cs 2 AgBiX 6 (X = Br, Cl). [9] The range of antimony (III) halides investigated in photovoltaic cells is limited to A 3 Sb 2 I 9 (A = MA, Rb, Cs). [10] Unfortunately, all binary and complex Bi(III) and Sb(III) halides so far tested delivered rather modest photovoltaic performances ranging from 0.1% to 1.2%. Low external quantum efficiencies (EQEs <20-30%) strongly suggest inefficient generation of charge carriers in the photo active layer and/or their hindered transport to the respective electrodes.Here, we report the first perovskite-like antimony (V) complex halide with the pseudo-3D crystal structure, which demonstrates EQE of ≈80% and decent power conversion efficiencies close to 4% in planar junction solar cells.While the photovoltaic properties of Sb(III) iodides have been intensively investigated within the last couple of years, halide complexes of Sb(V) remain unexplored. Yet, bromoantimonates (V) or so-called mixed valence complexes containing both Sb(III) and Sb(V) species were first reported more than 70 years ago. [11] These compounds represent intensively colored

Bromo‐ and Polybromoantimonates(V): Structural and Theoretical Studies of Hybrid Halogen‐Rich Halometalate Frameworks

“…The "non-ephemeral nature"a nd relative strength of such anionic contacts may be an explanation of the photovoltaic activity of (N-EtPy)[SbBr 6 ]r eported by us recently. [20] Therefore, these results mayb eo fi nterestb oth in terms of fundamental inorganic chemistry and materials science, in particularf or design of novel Pb-free, Sb-based solar cells.…”

“…[13][14][15][16][17][18][19] Recently it was found that bromoantimonates(V) can be utilized as components of perovskite-type solar cells. [20] Therefore, furtherresearch in this field is highly desirable. Analyzing previous research on this class of compounds, we have encountered av ery interesting series of articles by Jacobson et al, which appeared over 40 years ago.…”

Intermediate Bands in Zero-Dimensional Antimony Halide Perovskites

“…Following this analysis of the band structure it would be tempting to discuss its relation to the optical absorption profile of EtPySbBr6 as reported in ref. 35. The optical spectrum showed several distinct features across a wide energy range of 1.6 -3.9 eV.…”

Potential Substitutes for Replacement of Lead in Perovskite Solar Cells: A Review

“…ASbBr 2 is a black crystalline solid with an optical bandgap of 1.65 V that is much lower than that of conventional MAPbBr 3 of 2.3 eV. The planar cells with standard architecture using P3HT as a HTM layer displayed better photovoltaic parameters as J SC (5.1 mA cm −2 ), V OC (1.285 V), FF (0.58), and SPCE of 3.8% whereas the inverted architecture using a double‐layer PDI as ETL films is fabricated by depositing first by spin‐coating from chlorobenzene solution followed by evaporation of additional layers of the material in vacuum and has shown J SC of 5.1 mA cm −2 , V OC of 1.030 V, FF of 0.58, and SPCE of 3.1% only . The effect of substitution of antimony (Sb) with bismuth (Bi) in a 2D mixed layered perovskite (NH 4 ) 3 (Sb 1− x Bi x ) 2 I 9 as light absorber has been investigated extensively.…”