Stability and Efficiency Enhancement of Perovskite Solar Cells Using Phenyltriethylammonium Iodide

Abstract

Controlling the perovskite film surface is key to improving both the stability and photovoltaic performance of perovskite solar cells. In particular, surface defects on the perovskite films, which are fundamental issues, must be passivated. This work presents a 2D organic material phenyltriethylammonium iodide (PTEAI) to passivate a 3D (FAPbI3)1−x(MAPbBr3)x perovskite film surface. PTEAI forms a well‐matched conformal layer on the perovskite film, protecting the film surface from moisture by preventing the escape of organic ions from the film. The N+ cations and I− anions in PTEAI form bonds with the locally charged perovskite surface, reducing the surface defect density as well as the impeding non‐radiative recombination while enhancing carrier lifetimes. These PTEAI features facilitate significant enhancements in both the open‐circuit voltage (VOC) and fill factor (FF) of the perovskite solar cells. As a result, the champion PTEAI‐based perovskite solar cell exhibits the highest power conversion efficiency of 20.2% compared with 18.8% by the pristine device. Additionally, the PTEAI‐treated device retains 92% of its initial efficiency after being stored in ambient air at room temperature and a relative humidity of 40–60% for 500 h without encapsulation.

In situ surface regulation of 3D perovskite using diethylammonium iodide for highly efficient perovskite solar cells

“…26 After DAI treatment, new absorption peaks appear at 3024 and 766 cm À1 , which correspond to the symmetric stretching of the methylene (CH 2 ) group and the N-H wag from the secondary amine in DAI, respectively. 27 These new peaks indicate the successful incorporation of DAI on top of the 3D perovskite.…”

Efficient and Stable Perovskite Solar Cells by Tailoring of Interfaces

“…For stability, the devices based on PETAI maintained 92% of the original efficiency after aging for 500 h under continuous illumination in a high‐humidity atmosphere. [ 114 ] Jeong et al. compared the influence of alkyl chains of 2D cations of LDPHS on the photoelectric properties of PSCs (CHAI and CHAMI).…”

“…For stability, the devices based on PETAI maintained 92% of the original efficiency after aging for 500 h under continuous illumination in a high-humidity atmosphere. [114] Jeong et al compared the influence of alkyl chains of 2D cations of LDPHS on the photoelectric properties of PSCs (CHAI and CHAMI). The TRPL measurements showed that the samples based on 2D organic cation without alkyl chain modification exhibited faster interfacial carrier injection due to the lower valence band of perovskite surface.…”

Double‐Layer Quantum Dots as Interfacial Layer to Enhance the Performance of CsPbI3 Solar Cells

“…Interface engineering is an efficient and reliable strategy, which mainly through interface modification, adding buffer layers, dopant and so on to optimize interfacial contact and film morphology. [ 18–20 ] Appropriate interface engineering not only can achieve energy level alignment, but also passivate surface defects, which greatly improves the PCE of PSCs. [ 21,22 ] For instance, Xu et al.…”

“…Interface engineering is an efficient and reliable strategy, which mainly through interface modification, adding buffer layers, dopant and so on to optimize interfacial contact and film morphology. [18][19][20] Appropriate interface engineering not only can achieve energy level alignment, but also passivate surface defects, which greatly improves the PCE of PSCs. [21,22] For instance, Xu et al introduced the (CsPbI 2 Br) 1−x (CsPbI 3 ) x layer as intercalation layer between CsPbI 2 Br film and hole transport layer (HTL) to minimize the energy loss, resulting in good crystalline quality and energy level alignment.…”