Polymer-complexed SnO₂ electron transport layer for high-efficiency n-i-p perovskite solar cells

Abstract

Effective electron transport layer (ETL) plays a pivotal role in suppressing nonradiative recombination at interface, as well as promoting perovskite crystallization to facilitate electron extraction in solar cells (PSCs). Herein,...

Multifunctional Zwitterionic Modification of SnO2 in n–i–p Perovskite Solar Cells with Enhanced Fill Factor

“…Owing to the large surface area and significant internal van der Waals force of nanoparticles, they tend to agglomerate, forming irregular colloids. 25 According to previous studies, 26 oxygencontaining compounds with lone pair electrons can coordinate with Sn. Oxygen contributes these lone pair electrons to the empty d orbit of the metal atom, resulting in the formation of a metal−oxygen complex.…”

“…The molecular structure of AMSA is depicted in Figure S1a. Owing to the large surface area and significant internal van der Waals force of nanoparticles, they tend to agglomerate, forming irregular colloids . According to previous studies, oxygen-containing compounds with lone pair electrons can coordinate with Sn.…”

“…As shown in Figure g, AMSA-SnO 2 exhibited a higher transmittance compared to pristine SnO 2 in the wavelength range of 400–800 nm. The SnO 2 film’s surface defects, lumpy aggregates, and rough surface contributed to light refraction, reducing transmittability and overall light utilization. , To further study the electrical properties of the AMSA-SnO 2 film, the dark current–voltage ( I–V ) curve (Figure h) was analyzed, and the results revealed that the conductivity of AMSA-SnO 2 was higher than that of the SnO 2 film, indicating that the addition of AMSA could enhance the electron extraction ability and improve electron transport. Figure i illustrates the energy-level diagram of the device components obtained through UV photoelectron spectroscopy and ultraviolet–visible (UV–vis) absorption spectroscopy measurements (Figures S3 and S7).…”

Poly(acrylic acid)‐Modified SnO2 Electron Transport Layer for Perovskite Solar Cells

“…[15b] In order to study the effect of PAA on the conductivity of the SnO 2 films, the dark currentvoltage (I-V) curve confirmed that the ohmic conductivity of SnO 2 /PAA-2 was higher than the control (Figure 3b), which can be associated to the reduced surface defects of SnO 2 film and the improved free electrons donated by the PAA modification, also pushes the ETL/perovskite interfacial electron transport, and improves the short-circuit current density (J sc ) for PSCs. [19,29] However, in case of SnO 2 /PAA-1, the excessive insulation of PAA affects the conductivity of the relevant device, which may concur with a decreased device performance, and the SnO 2 / PAA-3 with the least PAA modification agent has a slight impact on the conductivity and corresponding device PCE, which will be discussed in the following section.…”

“…Many water‐soluble polymers have been utilized to suppress the issue of SnO 2 agglomeration in the suspension while passivate defects of both SnO 2 and perovskite. Examples include polyethylene glycol (PEG), [9c,16] poly(ethylene glycol) diacrylate (PEGDA), [17] polyethylene oxide‐polypropylene oxide‐polyethylene oxide (P123), [18] heparin potassium (HP), [9b] poly(amidoamine) (PM) dendrimer, [19] polyvinylpyrrolidone (PVP) and its derivatives, [20] polyacrylamide (PAM), [21] and ammonium polyacrylate (PANH 4 ), [22] etc. were reported, and mainly of them were uniformly dispersed in SnO 2 colloidal ink and promote the nanoparticle disaggregation in the ink, interact with both tin and oxygen dangling bonds, as well as hydroxyl groups in SnO 2 surface, complex with uncoordinated Pb 2+ to passivate defects, strengthen the interface contact between the ETL and the perovskite layer, and so on.…”