General Synthesis of Lead-Free Metal Halide Perovskite Colloidal Nanocrystals in 1-Dodecanol

Abstract

Lead halide perovskite nanocrystals (NCs) exhibit great application potential in optoelectronic devices because of their tunable band gaps and facile colloidal synthesis, but they suffer from serious lead toxicity and instability. It is highly desirable to substitute lead with other elements to acquire nontoxic and environmentally friendly lead-free perovskite NCs for optoelectronic devices. Here, we report a general method for the colloidal synthesis of a series of bismuth/antimony-based halide perovskite NCs with various constituents and optical band gaps from 1.97 to 3.15 eV. In our proposed synthetic system, 1-dodecanol is adopted as the solvent instead of the conventionally used 1-octadecene to realize size controllability of bismuth/antimony-based metal halide perovskite NCs. It is found that 1-dodecanol can act as a surfactant to tightly adsorb on the surface of bismuth/antimony-based halide perovskite NCs, enabling their small sizes (∼2 nm) and high dispersibility. Simultaneously, the band gaps of bismuth/antimony-based halide (A3B2X9, where A = CH3NH3, Cs, or Rb, B = Bi or Sb, and X = Cl, Br, or I) perovskite NCs can be systematically tuned by the atomic substitution of A, B, or X lattice sites. Moreover, to show the optoelectronic application potential of these lead-free halide perovskite NCs, a solar cell based on colloidal Cs3Bi2I9 perovskite NCs is demonstrated. The developed colloidal synthesis of bismuth/antimony-based halide NCs in 1-dodecanol will offer an alternative route to fabricating lead-free halide perovskite optoelectronic devices.

Dielectric Behavior of Mechano-chemically Synthesized [(CH3NH3)3Bi2Br9]: A Lead Free Hybrid Perovskite

“…XRD pattern of the mechanochemically-synthesized powder has been shown in Fig.1(a). The XRD peaks are in good agreement with the published Inorganic Crystal Structure Database (ICSD) 14 . We have generated the CIF for the simulation process of The complex impedance plot (Cole-Cole plot) i.e.…”

“…1(a). The XRD peaks are in good agreement with the published Inorganic Crystal Structure Database (ICSD) 14 . We have generated the CIF for the simulation process of the XRD pattern using Rietveld's refinement method.…”

Earth-abundant non-toxic perovskite nanocrystals for solution processed solar cells

“…Cs 3 Bi 2 I 9 NCs, with a band gap around 2 eV, were used to fabricate solar cells with SnO 2 as ETL and spiro-OMeTAD as HTL. The efficiency was 0.0103%, 93 which is far from the 9.2% of the bulk analogue. 86 However, in the bulk analogue, the PCE was enhanced by substituting spiro-OMeTAD by CuI as HTL.…”

“…The devices fabricated with these NCs used an almost identical solar cell structure with compact TiO 2 and spiro-OMeTAD as transport layers. 93,96 However, the device fabricated with Cs 2 Ag-BiBr 6 NCs, 96 that follows a ligand exchange process, showed better currents and V oc , pointing to the effectiveness of this approach in improving charge transport. A different selection of final ligands could further improve charge transport and adjust energy levels between the absorbing and transport layers, leading to better efficiencies.…”

Synthesis of Tungsten-Doped Vanadium Dioxide Using a Modified Polyol Method Involving 1-Dodecanol

“…In this study, we present a modified polyol method using 1-dodecanol as an additive to synthesize W x VO 2 (M). 1-Dodecanol has a boiling point of 259 • C, which is high enough for the polyol method, and can act as both the solvent and capping agent, as shown in inorganic nanoparticle synthesis [20]. Unlike the original polyol method, we found that tungsten could be doped into VO 2 (M) with the addition of 1-dodecanol, thereby reducing the MIT temperature of the resulting W x VO 2 (M).…”