Alfa Chemistry provides perovskite precursors for perovskite quantum dots and perovskite photoelectric components. In addition to precursor salts, we provide a range of precursor acids, halogen compounds, oxides and polymers as additives to adjust the structure of perovskite to achieve the desired physical properties.
Common Perovskite Precursors
Methylammonium Iodide (MAI)
Due to the high purity of ammonium methyl iodide (99.99%), it should be noted that its solubility in dimethylformamide and dimethyl sulfoxide is reduced. This has the potential to have an impact on the performance of the solar cell, resulting in a reduction in the maximum power conversion efficiency that can be achieved. The addition of a fixed concentration of hydriodic acid to the perovskite solution can improve the device's metrics. It is recommended that 1% to 10% of hydriodic acid be used with high-purity ammonium methyl iodide to achieve optimal device performance. The amount required depends on the precursor used, the concentration of the solution, the solvent used, and the processing environment.
Formamidinium Bromide (FABr)
Formamidinium bromide, used primarily as a perovskite precursor material for FAPbBr3 or a series of mixed lead iodide bromide perovskites (FAPbIyBr3-y). FAPbBr3 materials have an energy band gap of 2.23 eV, making them also ideal candidates for tandem solar cell applications.
N-butylammonium iodide (BAI), is commonly added to 3D perovskite precursor solutions to hinder the growth of 3D perovskite grains, greatly reducing the roughness of the film.
Compared to methylammonium iodide (MAI), it is believed that ammonium ions with longer chains will not fit into the corners of the PbX4 (X = I, Br, Cl) octahedral layer - leading to the formation of a layered perovskite (aka Ruddlesden Popper) structure. Layers doped with BAX show a dramatic improvement in the lifetime and operational stability of LED devices.
Aldibaja et al. have used halide (PbCl2) and non-halide lead precursors (Pb(OAc)2 (OAc=CH3CH2COO-), Pb(NO3)2, Pb(acac)2 (acac=(CH3COCH3)-) and PbCO3) to prepare perovskite solar cells. The growth of CH3NH3PbI3 was confirmed by X-ray diffraction in all analyzed cases, except for PbCO3, independent of the lead precursor of the synthetic perovskite. In addition, different cell structures, thin films and mesoporous scaffolds, TiO2 or Al2O3 were prepared. It was observed that the lead precursors have a strong influence on the structural properties (grain size) of the perovskite as well as on the performance of the solar cell. Using Pb(OAc)2 as the lead source, a photovoltaic conversion efficiency comparable to that obtained when using the commonly used PbCl2 was obtained. Stability studies of perovskite films and devices were also carried out, which showed that lead precursors also play a role. The stability was strongly influenced not only by atmospheric and light conditions, but also by the lead precursors used to synthesize the perovskites.
Fig. 1 SEM picture of CH3NH3PbI3 perovskite layer growth on a flat substrate with (a) PbCl2 and (b) Pb(OAc)2 lead precursors, and on a substrate with a mesoporous TiO2 scaffold with (c) PbCl2 and (d) Pb(OAc)2 lead precursors. Scale bar represents 100 nm. (Aldibaja et al., 2015)
Alfa Chemistry can provide a variety of complex and customized fluorescent quantum dot products. Our products involve perovskites precursors, perovskites quantum dots, quantum dot kit, single layer quantum dots, upconverting nanoparticles and other fluorescent quantum dots. Alfa Chemistry provides products with high fluorescence quantum yield, stable quality and relatively low price. Our products are constantly updated. If the product you need is not in our catalog, please feel free to contact us, we provide relevant custom services.
- Jin, H. H. , et al. Hysteresis-less inverted CH3NH3PbI3 planar perovskite hybrid solar cells with 18.1% power conversion efficiency[J]. Energy & Environmental Science, 2015, 8.
- Wei, Z. , et al. Enhanced optoelectronic quality of perovskite thin films with hypophosphorous acid for planar heterojunction solar cells[J]. Nature Communications, 2015, 6:10030.
- Xiao, Z. , et al. Efficient perovskite light-emitting diodes featuring nanometre-sized crystallites[J]. Nature Photonics, 11(2):108-115.
- Aldibaja, F. K. , et al. Effect of different lead precursors on perovskite solar cell performance and stability[J]. Journal of Materials Chemistry A, 2015, 3.
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