Fast Growth of Thin MAPbI₃ Crystal Wafers on Aqueous Solution Surface for Efficient Lateral‐Structure Perovskite Solar Cells

Abstract

Solar-grade single or multiple crystalline wafers are needed in large quantities in the solar cell industry, and are generally formed by a top-down process from crystal ingots, which causes a significant waste of materials and energy during slicing, polishing, and other processing. Here, a bottom-up technique that allows the growth of wafer-size hybrid perovskite multiple crystals directly from aqueous solution is reported. Single-crystalline hybrid perovskite wafers with centimeter size are grown at the top surface of a perovskite precursor solution. As well as saving raw materials, this method provides unprecedented advantages such as easily tunable thickness and rapid growth of the crystals. These crystalline wafers show high crystallinity, broader light absorption, and a long carrier recombination lifetime, comparable with those of bulk single crystals. Lateral-structure perovskite solar cells made of these crystals demonstrate a record power conversion efficiency of 5.9%.

Ambient Manipulation of Perovskites by Alternating Electric Field toward Tunable Photovoltaic Performance

“…Measurements have been first taken from top of perovskite with and without PCBM as the bottom layer to distinguish the influence of radiative recombination and charge transportation on the luminescence intensity. [55,56] In the case without PCBM, as shown in Figure 3a, the PL intensity of the AEF perovskite is at first (1 Hz) higher than the control sample, increases with increasing frequency until 20 Hz, and then decreases again to a value lower than the control sample. The high PL intensity at lower frequency (≤20 Hz) indicates weaker defect recombination and smaller trap density, as can be supported by the trap density space charge limited current measurements (Figures S15 and S16 in the Supporting Information).…”

Halide Perovskite Single Crystals: Optoelectronic Applications and Strategical Approaches

“…The PCE was hindered by the poling-induced high trap density as 1.88%. Later in 2019, the same group used the surface tension assisted growth method to synthesize single-crystalline thin films with a large aspect ratio and fabricate lateral-structure solar cells [79]. As illustrated in Figure 6i, in brief, by controlling the solvent evaporation of the precursor, nuclei favourably form at the centre of the solution top surface due to fast evaporation at the centre and float at the air-solution interface with the support from surface tension.…”

“…(i) Scheme of surface tension assisted growth mechanism; (j) scheme of MAPbI 3 crystal-wafer lateral-structure solar cell device. Reproduced with permission from[79]. Copyright 2019, WILEY-VCH.…”

Rapid Growth of Halide Perovskite Single Crystals: From Methods to Optimization Control

“…Huang's group grew MAPbI 3 single crystal wafers with thickness reduced to micrometers and lateral dimension of up to centimeters size within 30 min by introducing a driving force of solvent evaporation. [136] Not only these crystalline wafers exhibit high crystallinity, broader light absorption, and a long carrier recombination lifetime, which are comparable with those of bulk single crystals, but also it is praiseworthy that the crystal was directly grown from a more environment-benign aqueous solution instead of the commonly used organic solvents like DMF and GBL. Yan's group proposed top-down strategy to fabricate perovskite single-crystalline thin films.…”