Chlorine Incorporation for Enhanced Performance of Planar Perovskite Solar Cell Based on Lead Acetate Precursor

Abstract

We show the effects of chlorine incorporation in the crystallization process of perovskite film based on a lead acetate precursor. We demonstrate a fabrication process for fast grain growth with highly preferred {110} orientation upon only 5 min of annealing at 100 °C. By studying the correlation between precursor composition and morphology, the growth dynamic of perovskite film in the current system is discussed. In particular, we found that both lead acetate precursor and Cl incorporation are beneficial to perovskite growth. While lead acetate allows fast crystallization process, Cl improves perovskite crystallinity. Planar perovskite solar cells with optimized parameters deliver a best power conversion efficiency of 15.0% and average efficiency of 14.0% with remarkable reproducibility and good stability.

Monitoring Thermal Annealing of Perovskite Solar Cells with In Situ Photoluminescence

“…This recipe is based on a triple anion solution of lead acetate trihydrate (0.8 m), lead chloride (0.2 m), and methylammonium iodide (3.0 m) in dimethylformamide (DMF). [16,17] Applying a hot [22,24] solution (70 °C) onto spinning, preheated substrates in air reproducibly affords smooth perovskite films. After casting the perovskites are thermally annealed in ambient air at temperatures between 80 and 100 °C.…”

“…For example, various lead sources have been used in a single-step routine, such as lead acetate (Pb(OAc) 2 ), lead chloride (PbCl 2 ), and lead iodide (PbI 2 ), [15] or combinations thereof. [16,17] Other recipes that yield efficiencies exceeding 13% use different solvents, [18] nonsolvent washing, [19,20] alkyl halide additives, [21] acid additives, [22,23] hot casting, [23,24] and multistep processing routes. [3,25,26] The development of such a multitude of procedures is, at least in part, a consequence of the fact that it is not straightforward to reproduce the highest efficiency cells among different research groups.…”

Fabrication and Characterization of CH3NH3PbI3−x−yBrxCly Perovskite Solar Cells

“…Control of halogen doping with molar ratio between I, Cl and Br in perovskite crystal structure will provide the best condition for the photovoltaic performance, the crystal structure, carrier mobility and electronic electronic structure with band gaps between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and the optical properties with a wide range of absorption. The insertion of both Cl and Br into the perovskite structure promoted the carriergeneration, and expanded carrier diffusion and lifetime, along with reducing the charge recombination in the active layers for improving the photovoltaic performance [14][15][16][17][18][19][20]. A detailed description of the photovoltaic properties, structural analysis, and theoretical investigation using Xray diffraction pattern (XRD), X-ray photoelectron spectroscopy, scanning electronic microscopy (SEM) and density-functional theory calculation of halogen-doped perovskite layer of CH3NH3PbI3−xClx, CH3NH3PbBr3−xClx, CH3NH3SnX3 (X = Cl, Br, I), [HC(NH2)2]0.83Cs0.17Pb(I0.6Br0.4)3], antimony-doped CH3NH3PbI3, CH3NH3Pb1−xGexI3, CH3NH3Pb1−xTlxI3 and CH3NH3Pb1−xInxI3 on TiO2 layers has been reported [18][19][20][21][22][23][24][25][26][27][28][29].…”

Influence of the Preparation Method on Planar Perovskite CH3NH3PbI3-xClx Solar Cell Performance and Hysteresis

“…The Cl -in precursor solution can enhance crystallinity of the resulting perovskite films. The improved carrier transport has also been observed in MAPbI 3-x Cl x films with carrier diffusion length exceeding 1 µm, which is one order of magnitude larger than that of MAPbI 3 [15]. In addition, it has been mentioned for the first time by Snaith et al that introducing trace quantity of chlorine can dramatically improve electrical properties of perovskite materials [16].…”