The effect of mechanically milled lead iodide powder on perovskite film morphology

Lead iodide was precipitated from aqueous solutions of 0.015 - 0.1 M Pb(NO3)2 and 0.03 - 0.2 M KI in the equimolar ratio using a laboratory model of a stirred continuous crystallizer at 22 °C. After reaching the steady state, the PbI2 crystal size distribution was measured sedimentometrically and the crystallization kinetics was evaluated based on the mean particle size. Both the linear crystal growth rate and the nucleation rate depend on the specific output of the crystallizer. The system crystallization constant either points to a significant effect of secondary nucleation by the mechanism of contact of the crystals with the stirrer blade, or depends on the concentrations of the components added due to the micromixing mechanism.

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Batch Precipitation of Lead Iodide

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19941301 ◽

1994 ◽

Vol 59 (6) ◽

pp. 1301-1304

Author(s):

Jaroslav Nývlt ◽

Stanislav Žáček

Keyword(s):

Aqueous Solution ◽

Particle Size ◽

Particle Size Distribution ◽

Size Distribution ◽

Crystal Size ◽

Lead Nitrate ◽

Lead Iodide ◽

Constant Rate ◽

Mean Size ◽

The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

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Effects of 5-Ammonium Valeric Acid Iodide as Additive on Methyl Ammonium Lead Iodide Perovskite Solar Cells

Nanomaterials ◽

10.3390/nano10122512 ◽

2020 ◽

Vol 10 (12) ◽

pp. 2512

Author(s):

Daming Zheng ◽

Changheng Tong ◽

Tao Zhu ◽

Yaoguang Rong ◽

Thierry Pauporté

Keyword(s):

Solar Cells ◽

Perovskite Solar Cells ◽

Single Crystal Silicon ◽

Mesoporous Structure ◽

Valeric Acid ◽

Electrical Impedance Spectroscopy ◽

Lead Iodide ◽

Crystal Silicon ◽

Time Resolved ◽

Hole Transporting

During the past decade, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has risen rapidly, and it now approaches the record for single crystal silicon solar cells. However, these devices still suffer from a problem of stability. To improve PSC stability, two approaches have been notably developed: the use of additives and/or post-treatments that can strengthen perovskite structures and the use of a nontypical architecture where three mesoporous layers, including a porous carbon backcontact without hole transporting layer, are employed. This paper focuses on 5-ammonium valeric acid iodide (5-AVAI or AVA) as an additive in methylammonium lead iodide (MAPI). By combining scanning electron microscopy (SEM), X-ray diffraction (XRD), time-resolved photoluminescence (TRPL), current–voltage measurements, ideality factor determination, and in-depth electrical impedance spectroscopy (EIS) investigations on various layers stacks structures, we discriminated the effects of a mesoscopic scaffold and an AVA additive. The AVA additive was found to decrease the bulk defects in perovskite (PVK) and boost the PVK resistance to moisture. The triple mesoporous structure was detrimental for the defects, but it improved the stability against humidity. On standard architecture, the PCE is 16.9% with the AVA additive instead of 18.1% for the control. A high stability of TiO2/ZrO2/carbon/perovskite cells was found due to both AVA and the protection by the all-inorganic scaffold. These cells achieved a PCE of 14.4% in the present work.

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