Electrochemical Deposition of Organometallic Halide Perovskite Single-Crystal Particles with Density Gradients and Their Stability, Fluorescence, and Photoelectrochemical Properties

Abstract

Organometallic halide perovskites have gained immense scientific interest because of their unique optoelectronic properties that can benefit applications such as solar cells, lasers, and light-emitting diodes. Here, we develop a facile method to form a density gradient of MAPbI 3 (MA = methylammonium) crystal particles as a function of the electrochemical potential gradient across an indium-doped tin oxide (ITO) electrode. At the highpotential end of the ITO, a high density of nucleation sites is formed, yielding high-density MAPbI 3 crystals with a broad particle size distribution. Less density of MAPbI 3 crystals can be optically resolved at the low-potential end of the ITO. Spatial distributions of fluorescence and photoelectrochemical properties of the perovskite films show the same clear trends as the particle density gradients. Mass spectrum imaging of PbO 2 and MAPbI 3 gradients shows a spatial distribution of PbO 2 , MAPbI 3 of fresh sample and PbI 2 for aged sample. Mass spectrum imaging also reveals a poor structural stability of MAPbI 3 crystals formed at the high-potential side of the gradient because of their fast growth kinetics producing smaller nucleation sites.

Optimizing Perovskite Solar Cell Architecture in Multistep Routes Including Electrodeposition

“…There have been several attempts over the past few years to optimize the electrodeposited perovskite layer and adjust its crystallization on dissimilar layers. All subtechniques started by electrodepositing an initial layer (PbO, PbO 2 , or PbI 2 ) followed by one or several conversions of the as-deposited layer. − Cui et al and Huang et al both deposited PbO as a first step, before conversion into perovskite. , Cui chose a two-step conversion, first by exposing the as-prepared PbO films to iodine vapor and then converting into perovskite by immersion in methylammonium iodide (MAI) . He was able to develop a gold-electrode-based solar device with a 9% power conversion efficiency (PCE).…”

“…This offers great potential for production cost control. In the nine existing publications ,,− ,,, about perovskites obtained starting from electrodeposited PbO 2 , four use the galvanostatic mode and five use the potentiostatic mode. However, none of the galvanostatic studies have presented the PV data for MAPbI 3 .…”

Effect of Chlorine Addition on the Performance and Stability of Electrodeposited Mixed Perovskite Solar Cells

“…At the microscopic scale, the in-plane morphology of the different converted perovskites was studied by SEM and is presented in Figure c. After the conversion of PbI 2 in MAI, the MAPbI 3 surface is completely covered by small cubic-shaped grains with a nonuniform orientation, and a grain size ranging between 150 and 200 nm. ,,, When converting PbI 2 into MAPbI 3– x Cl x , we notice similar surface morphologies for the three films. It consists of cubic grains, a little bigger than MAPbI 3 , more entangled, and less spaced.…”

Bifunctional Chlorosilane Modification for Defect Passivation and Stability Enhancement of High-Efficiency Perovskite Solar Cells

“…In the context of global climate change and energy crisis, the research work on solar cells have attracted widespread attention from academia and industry. Since the advent of perovskite photovoltaics in 2009, its power conversion efficiency (PCE) has exceeded 25%, exhibiting strong competitiveness compared with the commercial photovoltaic technologies based on the inorganic materials such as Si, CuInGaSe, and GaAs. , The outstanding performance of perovskite material benefits from its excellent optical response ability, , ultra-long carrier diffusion length, , and high carrier mobility. , The convenient preparation process further contributes to its rapid development in the photovoltaic community. Generally, unlike the strict preparation conditions of inorganic photovoltaic materials, the polycrystalline perovskite films can be fabricated by facile solution spin-coating and annealing processes.…”

“…Since the advent of perovskite photovoltaics in 2009, 1 its power conversion efficiency (PCE) has exceeded 25%, 2 exhibiting strong competitiveness compared with the commercial photovoltaic technologies based on the inorganic materials such as Si, CuInGaSe, and GaAs. 3,4 The outstanding performance of perovskite material benefits from its excellent optical response ability, 5,6 ultra-long carrier diffusion length, 7,8 and high carrier mobility. 9,10 The convenient preparation process further contributes to its rapid development in the photovoltaic community.…”