A green Bi-Solvent system for processing high-quality CsPbBr3 films in efficient all-inorganic perovskite solar cells. (January 2022)

• Record Type: Journal Article
• Authors: Wang, Shibo; Cao, Fengxian; Sun, Weihai; Wang, Chunyan; Yan, Zhongliang; Wang, Nan; Lan, Zhang; Wu, Jihuai
• Is Part Of: Materials today physics. Volume 22(2022)
• Publication Date: 2022-01
• Subjects: All-inorganic perovskites -- CsPbBr3 -- Green solvent -- Triple-step solution method; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2022.100614
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: All-brominated inorganic perovskite CsPbBr3 has received much attention in the field of optoelectronic applications owing to its superb stability and ease of manufacture under the ambient condition. However, the tedious process and toxic solvent are two major challenges for fabrication of CsPbBr3 films via a multi-step deposition method. Here, we demonstrate a sustainable bi-solvent system for preparing high-quality CsPbBr3 films in a triple-step solution-processed route, where the bi-solvent system comprises of green solvent water and ethylene glycol monomethyl ether (EGME) in place of the noxious methanol for CsBr solution. By adjusting the temperature of heat treatment and spin-coating speed, the pinhole-free, ultra-smooth and high crystallinity of CsPbBr3 films were obtained. As a result, the CsPbBr3 PSC prepared from the green bi-solvent system demonstrates an optimal power conversion efficiency (PCE) of 9.55%, which is one of the highest efficiencies for planar carbon-based PSCs without hole transport layer. Moreover, the all-inorganic unpacked PSCs exhibit excellent humidity stability under ambient environment for 34 days. Our result not only offers a facile and simple way to fabricate the pure-phase CsPbBr3 films, but also alleviates the solvent toxicity during the preparation of CsPbBr3 PSCs. Graphical abstract: Benefiting from the high-quality of CsPbBr3 film with pinhole-free, pure phase and uniform surface, perovskite solar cell fabricated from a green bi-solvent system (water/EGME) exhibits an optimal power conversion efficiency of 9.55% and excellent moisture stability. Image 1 Highlights: A sustainable bi-solvent (including water and EGME) is used in place of the noxious methanol for CsBr solution. A simple and facile triple-step solution-processed route is proposed for the preparation of inorganic CsPbBr3 film. A phase-pure, continuous and pinhole-free CsPbBr3 film with high crystallinity is obtained. As a result, the solar cell based on the green bi-solvent solution delivers a champion efficiency of 9.55%.