Fabrication of CsPbBr₃ films with high quality using a simple method

Abstract

Inorganic perovskite CsPbBr3 is a material used for fabricating highly efficient and stable perovskite solar cells. In this work, a two-step infiltration-spinning method is proposed to obtain CsPbBr3 films with pure phase. Phase transformations between CsPb2Br5, CsPbBr3 and Cs4PbBr6 are investigated by controlling the contact time between the CsBr solution and the PbBr2 substrate. CsPbBr3 films with large grain sizes are obtained after high temperature post-treatment. The CsPbBr3-based solar cells show a high efficiency (approximately 7%) with a short-circuit current density of 6.68 mA cm−2, an open-circuit voltage of 1.47 V and a fill factor of 70.9% under standard solar illumination.

Improving the Quality of CsPbBr3 Films by Applying the Light Soak

“…The photograph results cannot infer whether the light soaking treatment affects the morphology. SEM images in Figure b illustrate that both films are stacked densely and consist of previous reports. , The crystallinity and morphology changes of the films are mainly driven by a thermal effect. , In the experiment, CsPbBr 3 films were annealed at 400 °C. The thermal effect of 400 °C is far stronger than that of light.…”

“…SEM images in Figure 2b illustrate that both films are stacked densely and consist of previous reports. 32,36 The crystallinity and morphology changes of the films are mainly driven by a thermal effect. 23,25 In the experiment, CsPbBr 3 films were annealed at 400 °C.…”

“…The 10 min high-temperature annealing is the optimized condition used in the study of CsPbBr 3 . 36,37 The J−V curve of the champion devices with light soaking is shown in Figure 3e. The reliability of J sc has been verified by IPCE (Figure 3f).…”

“…A compact layer of TiO 2 is subsequently deposited via spin coating an n -butanol solution of titanium diisopropyl diacetone (75 mg/mL) at 2000 rpm for 40 s, followed by annealing at 550 °C for 60 min. The CsPbBr 3 films are prepared using the infiltration spin coating method in the air according to the previous work . First, a PbBr 2 /DMF solution (1 mol/L) is spin-coated onto the TiO 2 layer with 100 μL of the ACN anti-solvent in the process.…”

“…The CsPbBr 3 films are prepared using the infiltration spin coating method in the air according to the previous work. 36 First, a PbBr 2 /DMF solution (1 mol/L) is spin-coated onto the TiO 2 layer with 100 μL of the ACN anti-solvent in the process. Second, the PbBr 2 precursor films are warmed at 90 °C for 10 min.…”