Highly Efficient and Air‐Stable Inorganic Perovskite Solar Cells Enabled by Polylactic Acid Modification

Abstract

Inorganic perovskite solar cells (PSCs) suffer from serious carrier recombination and open‐circuit voltage loss because of surface defects and unfavorable energy level alignment. Herein, a polylactic acid (PLA) modification approach to improve the performance of mixed‐halide inorganic perovskites is reported. First, the surface defects are effectively passivated through strong interaction between C═O in PLA and undercoordinated Pb2+. Second, secondary grain growth is induced by PLA modification, resulting in larger grain sizes. Third, PLA modification makes the surface region of perovskite change from n‐ to p‐type, favoring charge transport from perovskite to the hole transport layer (HTL). The PLA modified films enable PSCs with less nonradiative recombination and lower energy loss. Consequently, record PCEs of 19.12% and 18.05% are achieved for CsPbI2.25Br0.75 and CsPbI2Br PSCs, respectively. The PSC with an active area of 1 cm2 shows a PCE of 16.41%. A PCE of 14.70% is achieved for HTL‐free PSC with carbon electrode. In addition, the PSC with PLA modification shows significantly improved air stability due to the hydrophobic PLA coating. This work suggests that PLA surface modification is an effective approach to achieving efficient, stable, scalable, and low‐cost inorganic PSCs.

A study of polylactic Acid/K2SiF6:Mn4+ composite luminescent materials: design, preparation, and properties

“…As one of the promising biobased polymers, polylactic acid (PLA) has received extensive attention because of its renewable raw materials (such as corn and sugarcane) and degradable products after disposal [1][2][3]. Regarding performance among biobased polymers, it is known as the most promising biobased polymer with good processing performance and mechanical strength.…”

“…In addition, PLA and its copolymers are used in engineering because of their excellent biocompatibility and mechanical properties [6,7]. For instance, a PLA modification approach was reported to improve the performance of mixed-halide inorganic perovskites solar cells [3]. Besides being an eco-friendly nontoxic polymer with features that permit use in the human body, PLA is an essential polymeric material for more eco-friendly applications [3,8].…”

Semi‐transparent metal electrode‐free all‐inorganic perovskite solar cells using floating‐catalyst‐synthesized carbon nanotubes

“…[33][34][35][36][37][38] Although initially constrained by a low PCE, concerted international research endeavors successfully increased the PCE to 18.05%. 39 Recently reported CPIB PSCs demonstrated device stability times exceeding 1000 h under ambient conditions, even without encapsulation. [40][41][42][43] This is a significant advancement compared to organic-inorganic PSCs, which typically demonstrate stability between 100 and 300 h. [44][45][46][47][48] Further enhancement of all-inorganic PSCs can be achieved by replacing the top metal electrode with hydrophobic carbon electrodes, which inhibit moisture penetration and metal ion migration.…”

Comparative study of distinct halide composites for highly efficient perovskite solar cells using a SCAPS-1D simulator

“…27 These PSCs have their own set of advantages and disadvantages, such as high efficiency and stability but poor performance, high stability but not eco-friendly, and so on. [28][29][30][31][32][33][34] These issues can be addressed through improved engineered devices, encapsulation, and the use of 2D perovskites. Milot et al veried that FASnI 3 had higher carrier mobility, lower auger recombination rate constants, and a more substantial radiative rate of recombination constant that is comparable to GaAs.…”