Enhanced Crystallization by Methanol Additive in Antisolvent for Achieving High‐Quality MAPbI₃ Perovskite Films in Humid Atmosphere

Abstract

Perovskite solar cells have attracted considerable attention owing to their easy and low-cost solution manufacturing process with high power conversion efficiency. However, the fabrication process is usually performed inside a glovebox to avoid moisture, as organometallic halide perovskites are easily dissolved in water. In this study, we propose a one-step fabrication of high-quality MAPbI perovskite films in around 50 % relative humidity (RH) humid ambient air by using diethyl ether as an antisolvent and methanol as an additive into this antisolvent. Because of the presence of methanol, the water molecules can be efficiently removed from the gaps of the perovskite precursors and the perovskite film formation can be slightly controlled, leading to pinhole-free and low roughness films. Concurrently, methanol can be used to tune the DMSO ratio in the intermediate perovskite phase to regulate perovskite formation. Planar solar cells fabricated by using this method exhibited the best efficiency of 16.4 % with a reduced current density-voltage hysteresis. This efficiency value is approximately 160 % higher than the devices fabrication by using only diethyl ether treatment. From the impedance measurement, it is also found that the recombination reaction is suppressed when the device is prepared with methanol additive in the antisolvent. This method presents a new path for controlling the growth and morphology of perovskite films in humid climates and laboratories with uncontrolled environments.

All‐Inorganic CsPb1−xGexI2Br Perovskite with Enhanced Phase Stability and Photovoltaic Performance

“…As it is known that lower Rs suggests a better electro transport and larger R rec implies the lower recombination rate. According to Figure S10, the solar cell device based on CsPb 0.8 Ge 0.2 I 2 Br has a much higher R rec than that of CsPbI 2 Br which determined from the width of the semicircle, suggesting the recombination rate is decreased by Ge incorporation . Therefore, it can be concluded that the larger R rec of Ge incorporated perovskite device indicates that the carrier mobility in correspondent device is improved thus leading to enhanced V oc and FF.…”

Crystalline Clear or Not: Beneficial and Harmful Effects of Water in Perovskite Solar Cells

“…[21] Their sophisticated setup consisted in an atmospheric box of controllable RH, where dry N 2 was used as the carrier gas, flowing through a set of water bubblers into the atmospheric bag (Figure 4a). [51] In their work, methanol is used as an additive onto the diethylether antisolvent to remove the residual water occluded in the perovskite material during first steps of crystallization (Figure 4b). [50] More recently, an interesting additive-antisolvent method under room conditions has been proposed by Yang et.al.…”

“…[50] More recently, an interesting additive-antisolvent method under room conditions has been proposed by Yang et.al. [51] In their work, methanol is used as an additive onto the diethylether antisolvent to remove the residual water occluded in the perovskite material during first steps of crystallization ( Figure 4b). They proposed an enhanced crystallinity lacking of pinholes and reduced hysteretic behaviour in devices prepared with their method, attributing this effect to a fast extraction of water molecules during the annealing step, as methanol has high water solubility.…”

Bulk and Interfacial Engineering to Enhance Photovoltaic Properties of Iodide and Bromide Perovskite Solar Cells

“…A wide number of methods have been developed to detect and quantify the ionic diffusion rates. Photothermal induced resonance (PTIR), kelvin probe force microscopy (KPFM), 207 Pb NMR, 127 I NMR/NQR, tracer diffusion, reaction cell, doping experiments, galvanostatic measurement, impedance spectroscopy (IS) or suppression of luminescence in laterally contacted electrodes, are some of the main responsible techniques which provides evidences of ionic migration and specific values of their diffusion coefficients (Table 1). 79,80,81 A recent review published by Wang et.al.…”

“…al. 127,128 In their work, methanol is used as an additive onto the diethylether antisolvent to remove the residual water occluded in the perovskite material during first steps of crystallization ( Fig.1.33b). They proposed an enhanced crystallinity lacking of pinholes and reduced hysteretic behaviour in devices prepared with their method, attributing this effect to a fast extraction of water molecules during the annealing step, as methanol has high water solubility.…”