One-Step Spray-Coated All-Inorganic CsPbI₂Br Perovskite Solar Cells

Abstract

Here, we report a scalable ultrasonic spray deposition under ambient conditions to fabricate a CsPbI2Br-based all-inorganic perovskite thin film for photovoltaic applications. With the cooperated aid of vacuum extraction of the as-fabricated perovskite film and the incorporation of lead­(II) acetate (Pb­(Ac)2) additive to the precursor solution, the quality of the perovskite film dramatically improved from the filled pinholes between the crystal grain with enhanced perovskite crystallinity. We found that the champion device for the 5% Pb­(Ac)2-doped CsPbI2Br perovskite film combined with vacuum extraction achieved the best power conversion efficiency (PCE) of 10.06%, arising from the efficient defect dissipation within the film and the reduction in the charge recombination loss. Simultaneously, the thermal stability was boosted with the incorporation of Pb­(Ac)2 after aging at 85 °C for 10 days. We believe that the spray-coating process combined with the optimization of the all-inorganic perovskite film will help in the fabrication of a photoabsorbing layer for the future industrial upscaling of perovskite solar cells.

Simple-Structured Low-Cost Dopant-Free Hole-Transporting Polymers for High-Stability CsPbI2Br Perovskite Solar Cells

“…Moreover, the charge transport, recombination, and molecular ordering properties of dopant-free PCDA1-based devices were highly similar to those of state of the art doping-assisted spiro-OMeTAD-based devices, which yielded a PCE comparable to that of doped spiro-OMeTAD-based devices (12.22%). In addition, our dopant-free PCDA1-based devices showed much higher PCE in comparison to those (8.8%) based on poly­(triarylamine) (PTAA) HTMs having a molecular structure similar to that of PCDA1 …”

“…In addition, our dopant-free PCDA1-based devices showed much higher PCE in comparison to those (8.8%) based on poly(triarylamine) (PTAA) HTMs having a molecular structure similar to that of PCDA1. 32 Notably, the shelf life, thermal stability, and photostability of dopant-free PCDA1-based PSCs were superior to those of the doped and dopant-free spiro-OMeTAD-based devices. In a test ofshelf life stability, the doped and dopant-free spiro-OMeTAD-based devices were exhausted after 20 and 120 h, respectively, whereas 86% and 78% of the initial PCEs were retained in the dopant-free PCDA1-and PCDA2-based devices, respectively, after 120 h. In the case of thermal stability, the PCEs of spiro-OMeTAD-based devices significantly dropped to 25% of their initial efficiency within 2 days at 85 °C, whereas both dopant-free PCDA1-and PCDA2-based devices still maintained 90% of their initial efficiency under identical conditions.…”

Progress in Spray Coated Perovskite Films for Solar Cell Applications

“…With the synergistic aid of vacuum pumping and the incorporation of a Pb(OAc) 2 additive, a champion device was achieved with a PCE of 10.1% and its thermal stability was boosted after aging at 85 °C for 10 days. [ 30 ] Additionally, Yuan et al have also fabricated inorganic perovskite CsPbI 3 quantum dot (QD) films using a fully automated spray coating process that can be carried out without a glove box. [ 31 ] Furthermore, after strategically modifying the colloidal QD surfaces with phenyltrimethylammonium bromide (PTABr), Yuan et al successfully shortened the inter‐QD distances and consequently boosted charge carrier mobilities.…”

Fully Scalable and Stable CsPbI2Br Solar Cells Realized by an All-Spray-Coating Process

“…Since then, many studies have reported on the deposition of the MHP layer via ultrasonic spray-coating for solar cell devices, and recent studies have successfully demonstrated the spray-coating of all-inorganic CsPbI 3−x Br x layers for highly efficient inorganic MHP solar cells. 17,22,33 For n-i-p-type MHP solar cell devices, spray pyrolysis of the compact TiO 2 (c-TiO 2 ) layer is a widely accepted method for depositing a compact, uniform, and thin electron transport layer (ETL). 17,[21][22][23]26,30,35 On the other hand, only few studies have reported on the spray-coated development of hole transport layers (HTLs), thus marking the HTL as the bottleneck toward developing fully spray-coated inorganic MHP solar cells.…”

“…Spray-coating is a simple and continuous process that can easily conform to the substrate shape while exhibiting fast throughput and high material consumption with little regard to chemical orthogonality. , Additionally, due to the continuous supply of precursor solution droplets on the substrate during spray-coating, crystallization of low-soluble all-inorganic MHPs can be controlled, and thus, a uniform film across a large area can be realized . Overall, spray-coating has emerged as a strong candidate for the fabrication and upscaling of MHP solar cells, and many researchers have demonstrated the development of efficient and scalable MHP solar cells by spray-coating. ,,− Therefore, it is also expected that a complete transition from spin-coating to all-spray-coating would result in a scalable, timely, and cost-efficient MHP solar cell manufacturing process with the additional privilege of being able to apply patterns when needed, as long as the high photovoltaic performance is preserved.…”