Stabilization of Inorganic CsPb_0.5Sn_0.5I₂Br Perovskite Compounds by Antioxidant Tea Polyphenol

Abstract

Implementation of inorganic perovskite compounds and reduction toxicity of lead are important for developing sustainable and renewable photovoltaic power generation. The inorganic Pb/Sn binary metal halide perovskites offer a perfect opportunity for tuning optical bandgap and thus hold significant potential in emerging technologies such as solar cells. However, an easy oxidation of Sn2+ to Sn4+ has become one of the main issues for achieving efficient and stable Sn‐based perovskite solar cells (PSCs). Herein, an effective method for stabilizing CsPb0.5Sn0.5I2Br is proposed to realize high‐efficiency PSCs via antioxidant tea polyphenol (TP). It is found that TP can not only slow down the oxidation of Sn2+ but also regulate perovskite film crystallization during the formation of perovskite films via coordination interaction, leading to a reduced density of defects and an enlarged open‐circuit voltage. The resultant perovskite solar cell using CsPb0.5Sn0.5I2Br (TP) with an all‐inorganic mesoscopic framework of FTO/c‐TiO2/m‐TiO2/Al2O3/NiO/carbon achieves an impressive power conversion efficiency of 8.10% with high stability.

Recent Progress and Challenges toward Highly Stable Nonfullerene Acceptor‐Based Organic Solar Cells

“…The use of stabilizers such as antioxidizing agents to regulate the detrimental chemical reactions and inhibit the photooxidation of the photoactive materials may be a promising strategy to enhance the stability of NFA OSCs, considering the successful application of several stabilizers in biology, perovskite solar cells (PSCs), and polymer:fullerene OSCs. [ 178,225–228 ] For example, the inexpensive natural antioxidants uric acid, [ 229 ] tea polyphenol, [ 230 ] and ascorbic acid [ 231 ] have been used in tin‐based PSCs to prevent the oxidation Sn 2+ , thereby resulting in significantly improved device stability. It has been found that a set of structurally varied hindered phenols can stabilize the lifetime of P3HT:PCBM devices without compromising their performance, owing to the hydrogen donation and radical scavenging properties of hindered phenols which can significantly reduce the radicals within the photoactive layer.…”

Fully Inorganic CsSnI3 Mesoporous Perovskite Solar Cells with High Efficiency and Stability via Coadditive Engineering

“…[12][13][14][15] However, the inferior stability and low device performance of CsSnI 3 -based PSCs have been widely observed, which originate mainly from the chemical instability of Sn 2þ component and nonuniform perovskite crystalline layers. [16,17] As an essential inhibitor of Sn 4þ , SnF 2 has been reported to decrease the conductivity of tin-based perovskites and alleviate the oxidation of Sn 2þ . [18] SnF 2 also acts as a tin compensator to supply Sn 2þ .…”

Sn/Pb binary metal inorganic perovskite: a true material worthy of trust for efficient and stable photovoltaic application

“…The elements of Sn and Pb within the same main group have similar ns 2 np 2 electronic configuration [6][7][8][9]. Especially, the Snbased perovskites are promising for solar energy harvesting in view of ideal optical bandgaps (1.2-1.4 eV), high optical absorption coefficient as well as high carrier mobility (~585 cm 2 V À1 s À1 ) [10,11].…”

“…One major drawback of Sn/Pb binary metal inorganic perovskites is their low chemical stability due to an easy Sn 2+ oxidation. To deal with this issue, antioxidant tea polyphenol was proposed to stabilize CsPb 0.5 Sn 0.5 I 2 Br (with an optical bandgap of 1.44 eV) as light absorber in solar cells using all-inorganic TiO 2 /Al 2 O 3 /NiO/carbon framework [9]. The optimized device exhibited an impressive PCE of 8.10% as well as decent operational stability (maintained 90.1% of its initial PCE under AM 1.5G one sun illumination with maximum power point tracking for 200 h in N 2 filled glove box).…”

“…In the past few years, we do see some breakthroughs in Sn/Pb binary metal inorganic PSCs with short circuit current density exceeding 25 mA cm À2 , and PCE exceeding 13% [8]. However, the easy oxidation of Sn 2+ to Sn 4+ (which induces high defect density and low minority carrier lifetime) remains the main obstacle [8,9]. Therefore, significant strategies that considering the intrinsic chemical nature of tin are required to mitigate Sn 2+ oxidation to further enhance PCE and stability of Sn/Pb binary metal inorganic PSCs.…”