Parylene-Sealed Perovskite Nanocrystals Down-Shifting Layer for Luminescent Spectral Matching in Thin Film Photovoltaics

Abstract

The present contribution aims to enhance solar cells’ performance via the development of advanced luminescent down-shifting based on encapsulated nanostructured perovskite materials. Here, thin films of inorganic lead halide (CsPbBr3) perovskite nanocrystal luminophores were synthetized, by hot-injection, deposited on glass substrates by spin-coating, and encapsulated with parylene type C, via chemical vapor deposition, to protect and stabilize the films. The optical properties of these thin films were characterized by absorption, emission and 2D contour spectra, their structure by X-ray diffraction and X-ray photoelectron spectroscopy, and the morphology by Scanning Transmission Electron microscopy. I–V curve and spectral response nanocrystalline silicon photovoltaic (nc-Si:H PV) cells were studied in the absence and presence of the perovskite and parylene luminescent down-shifting layers. The incorporation of the CsPbBr3 nanocrystals and their encapsulation with the parylene type C polymeric coating led to an increase in the current generated and the spectral response of the PV cells in the regime of the nanocrystals’ fluorescence emission. A 3.1% increase in the short circuit current density and a 5.6% increase in the power conversion efficiency were observed.

Defect-Passivated Photosensor Based on Cesium Lead Bromide (CsPbBr3) Perovskite Quantum Dots for Microbial Detection

“…Also, XPS showed F 1s and Cl 2p peaks after parylene-F and parylene-C coating, respectively. These XPS results indicated the interaction of the halides of the parylene with the halide vacancies of perovskite, and the improved stability after parylene coating. , …”

“…Also, the PL peaks of the CsPbBr 3 perovskite QD changed after coating with parylenes, as shown in Figure S3. When the PL peak of CsPbBr 3 after parylene coating was compared with the CsPbBr 3 QD without parylene (493 nm), the PL peak blue-shifted to 489 nm for parylene-N, 460 nm for parylene-F, and 452 nm for parylene-C. PL peaks after the deposition of parylenes with functional groups (–F, –C) significantly changed to indicate the interaction between the perovskite QD and functional groups of the parylene film . To investigate the influence of functionalized parylenes (chloride from parylene-C and fluoride from parylene-F), the bandgap energies of the perovskite QD were compared with those of parylene films with halides (parylene-C and parylene-F) and unmodified ones (parylene-N).…”

“…These XPS results indicated the interaction of the halides of the parylene with the halide vacancies of perovskite, and the improved stability after parylene coating. 21,39 The geometry of the perovskite with vacancies, fluoride, and chloride was optimized by ab initio density functional theory (DFT) calculations using the CAM-B3LYP/LANL2DZ basis set (Gaussian 09 program). The optimized structures are shown in Figure 6a.…”

“…When the PL peak of CsPbBr 3 after parylene coating was compared with the CsPbBr 3 QD without parylene (493 nm), the PL peak blue-shifted to 489 nm for parylene-N, 460 nm for parylene-F, and 452 nm for parylene-C. PL peaks after the deposition of parylenes with functional groups (−F, − C) significantly changed to indicate the interaction between the perovskite QD and functional groups of the parylene film. 21 To investigate the influence of functionalized parylenes (chloride from parylene-C and fluoride from parylene-F), the bandgap energies of the perovskite QD were compared with those of parylene films with halides (parylene-C and parylene-F) and unmodified ones (parylene-N). As previously reported, the valence band maximum (VBM) values were estimated using X-ray photoelectron spectroscopy (XPS) by determining the intersection between the linearly fitted line at the edge of the valence band and flat energy distribution in the valence band spectra.…”

Study on the effect of chain extenders on aliphatic polyurethane and its application

“…Laminated glass consists of a polymer elastic layer and glass. [1][2][3][4] It is significant to investigate the performance between polymer film and glass. Common intermediate films used in laminated glass include polyvinyl butyral (PVB) and others.…”