Highly efficient and stable perovskite solar cells produced by maximizing additive engineering. Issue 2 (8th December 2020)

• Record Type: Journal Article
• Authors: Qiu, Linlin; Zou, Jiacheng; Chen, Wei-Hsiang; Dong, Lika; Mei, Deqiang; Song, Lixin; Wang, Jieqiong; Jiang, Pei-Cheng; Du, Pingfan; Xiong, Jie
• Is Part Of: Sustainable energy & fuels. Volume 5:Issue 2(2021)
• Page Start: 469
• Page End: 477
• Publication Date: 2020-12-08
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/d0se01498b
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : The crystallinity of a perovskite film can play a key role in the photovoltaic performance and long-term stability of perovskite solar cells (PSCs). Abstract : The crystallinity of a perovskite film can play a key role in the photovoltaic performance and long-term stability of perovskite solar cells (PSCs). Herein, we introduce 4- tert -butylpyridine ( t BP) into perovskite on the reduction-active poly(3, 4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hole transport layer and maximize its morphology-regulating effect via enhancing the concentration of CH3 NH3 I used in the two-step spin-coating. Since the high concentration iodine methylamine increases the oxidation potential, a perovskite film with large grains can be obtained. Furthermore, we proposed using a small amount of t BP with a high concentration of CH3 NH3 I and found that it would form a gradient structure in the perovskite. A small amount of t BP in CH3 NH3 I can further enhance its diffusion mobility into PbI2 films. Moreover, t BP in perovskite with a gradient structure can further induce coordination between t BP and perovskite, leading to considerably large perovskite grains (∼1.4 μm) with defect-free morphology. The perovskite grains can be more completely surrounded by the stronger hydrophobic t BP. Therefore, both the efficiencies and moisture stabilities of the PSCs can be significantly enhanced. PSCs without encapsulation could even maintain more than 80% of their initial PCE after 400 h of moisture exposure (RH ∼50%). Moreover, the flexible devices after optimization could achieve a PCE of 14.92%, and still maintain at 11.39% after 20 times of mechanical bending.