Heterogeneous Supersaturation in Mixed Perovskites

Abstract

Thin‐film solar cells based on hybrid lead halide perovskites have achieved certified power conversion efficiencies exceeding 24%, approaching those of crystalline silicon. This motivates deeper studies of the mechanisms that determine their performance. Twin defect sites have been proposed as a source of traps in perovskites, yet their origin and influence on photovoltaic performance remain unclear. It is found that twin defects—observed herein via both transmission electron microscopy and X‐ray diffraction—are correlated with the amount of antisolvent added to the perovskite and that twin defects in the highest‐performing perovskite photovoltaics are suppressed. Heterogeneous supersaturation nucleation is discussed as a contributor to efficient perovskite‐based optoelectronic devices.

Broad-Band Photodetectors Based on Copper Indium Diselenide Quantum Dots in a Methylammonium Lead Iodide Perovskite Matrix

“…As mentioned above, CISe QDs were not only evenly distributed on the perovskite surface but also in the interior of the film (e.g., at grain boundaries), where they provided numerous nucleation centers for MAPbI 3 crystals. As previously reported, the accelerated nucleation process can enhance the perovskite crystallinity and reduce the twin defects in perovskite films. , As a result, OLA ligands and CISe QDs together were able to passivate the whole of the perovskite films, with a combined best improvement in the MAPbI 3 /CISe5.6% case of a 10-fold increased average PL lifetime.…”

Optoelectronic Properties Prediction of Lead-Free Methylammonium Alkaline-Earth Perovskite Based on DFT Calculations

“… 1 − 5 The organic–inorganic perovskite materials could be potential candidates for ultrawide band-gap optoelectronics due to their excellent carrier mobility and lifetime, high flexibility, and low formation temperature. 6 − 9 However, there is a lack of high external quantum efficiency (EQE) material for ultraviolet C devices (4.42–12.4 eV), and a new type of organic–inorganic perovskite could offer a solution. The density functional theory (DFT) calculation can determine the electronic structure and phonon dispersion diagram for the electrical and dynamic stability property of new organic–inorganic perovskite structures and determine the possibility for device application.…”

Theoretical framework and experimental methodology to elucidate the supersaturation dynamics of nanocrystal growth

“…Supersaturation is the fundamental, non-equilibrium parameter that drives crystal formation and influences the growth mechanism, shape, exposed facets, crystal habit, size, and uniformity of NCs. 8,32–35 It is defined aswhere C is the monomer concentration, C 0 is the saturation concentration of the monomer, Δ μ is the chemical-potential difference between monomeric units and integrated units in the crystal, and k B T is the thermodynamic temperature. To form NCs, synthesis formulations modulate C above the saturation (enabling growth if nuclei are present) or nucleation limits.…”

“…30,31 Supersaturation is the fundamental, non-equilibrium parameter that drives crystal formation and influences the growth mechanism, shape, exposed facets, crystal habit, size, and uniformity of NCs. 8,[32][33][34][35] It is defined as…”