Grain boundaries passivation of high efficiency and stable perovskite photodetector by polyoxometalate-based composite SiW ₁₁@ZIF-8

Abstract

Polyoxometalates (POMs) can enable energy level tuning to match perovskite layers. They are considered electronic bridges to modify perovskite and improve the performance of photovoltaic devices. Therefore, in the present work, we dispersed the vacancy POMs K 8 [α-SiW 11 O 39 ]•H 2 O ({SiW 11 }) in the metal-organic frameworks (MOFs) to modify the perovskite layer. {SiW 11 } could adjust the energy level between the layers of the perovskite photodetector. Moreover, the hydrogen bonds formed between SiW 11 @ZIF-8 and perovskite effectively passivated the grain boundaries (GBs) of the perovskite layer. Xray diffraction spectroscopy (XRD) showed that the crystallinity of perovskite was significantly improved. In addition, scanning electron microscopy (SEM) images demonstrated that the average size of perovskite grains increased from 254.50 to 719.27 nm, proving the effective passivation of the GBs. Furthermore, a series of tests such as infrared spectroscopy (IR), N 2 adsorption/desorption isotherms, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) also proved that {SiW 11 } could be successfully loaded into the pores of ZIF-8 through electrostatic interactions. The photocurrent of the SiW 11 @ZIF-8 doped device reached 41.95 μA, about three times as high as that of the blank device (14.41 μA). Also, under unencapsulated conditions, it could still maintain more than 90% stability for nearly 700 h.

The tail of imidazole regulated the assembly of two robust sandwich-type polyoxotungstate-based open frameworks with efficient visible-white-light-driven catalytic oxidation of sulfides

“…Visible-light-driven organic conversion is one of the prospective strategies to directly effectuate chemical bond functionalization under ambient conditions. 1–3 The promising strategy could synchronously ameliorate widespread concerns over energy crisis and environmental issues, pursuing sustainable and high-quality development of chemical industries. 4 Among these photocatalytic organic transformations, the selective aerobic oxidation of sulfides is one of the paramount methods to produce high value-added sulfoxides.…”

Morphologically controlled synthesis, characterization, and applications of molybdenum oxide (MoO3) nanoparticles

“…[29] Moreover, molecular molybdenum oxides are being studied extensively in literature. [30][31][32][33][34][35]…”

Study on the incorporation of various elements into the Keggin lacunary-type phosphomolybdate [PMo9O34]9− and subsequent purification of the polyoxometalates by nanofiltration

“…4,5 Furthermore, there are applications for POMs acting as proton conductors or as motifs to modify perovskite and metal organic framework (MOF) materials to use the resulting compounds in photovoltaic applications. 1,[6][7][8][9][10] Due to their unique properties, an inorganic POM structure can be combined with an organic cation. The resulting hybrid materials are interesting for nanoscience and biobased applications.…”