Polyiodide-assisted fabrication of hybrid perovskite thin films from lead nanolayers on flexible substrates

Despite remarkable progress in solvent-assisted processing of hybrid perovskite thin films, the scalable fabrication of their uniform and pin-hole free layers remains a difficult task, especially on flexible substrates. In contrast, we have demonstrated that the polyiodide-assisted conversion of Pb nanolayers into MAPbI3 results in the formation of crystalline MAPbI3 thin films on large flexible substrates already at the room temperature. The exposure of stoichiometric Pb/MAI bilayers to iodine vapor leads to the formation of highly reactive polyiodide melts MAI3(L), which instantly react with the Pb nanolayers converting them into pure MAPbI3 films without byproducts or unreacted components.

Bilayered Two-Dimensional Hybrid Perovskite with the Cage-Templated Secondary Cation for High Efficiency Photodetection

Two-dimensional (2D) multilayered hybrid perovskites adopting the intrinsic quantum-well structures have shown great application potentials in the field of optoelectronics. Despite extensive studies, the candidate perovskites composed of the cage-templated...

Спектры пропускания монокристаллов гибридных перовскитов MAPbI-=SUB=-3-=/SUB=- вблизи края фундаментального поглощения

The paper presents the transmission spectra of hybrid perovskite MAPbI3 single crystals near the fundamental absorption edge in a wide temperature range. The absorption coefficient α of the single crystal samples is estimated at a temperature T = 150 K for the light with a photon energy E = 1.6 eV and at T = 40 K for E = 1.8 eV. The obtained values turned out to be several orders of magnitude smaller than the values of α for thin-film samples known from the literature. A sharp shift of the fundamental absorption edge by ~ 100 meV was observed at a temperature T1 = 160 K of the structural phase transition from the tetragonal to the orthorhombic phase. The temperature hysteresis of the shift of the fundamental absorption edge near T1 was recorded, which is characteristic of a first-order phase transition.

A flexible capacitive photoreceptor for the biomimetic retina

Neuromorphic vision sensors have been extremely beneficial in developing energy-efficient intelligent systems for robotics and privacy-preserving security applications. There is a dire need for devices to mimic the retina’s photoreceptors that encode the light illumination into a sequence of spikes to develop such sensors. Herein, we develop a hybrid perovskite-based flexible photoreceptor whose capacitance changes proportionally to the light intensity mimicking the retina’s rod cells, paving the way for developing an efficient artificial retina network. The proposed device constitutes a hybrid nanocomposite of perovskites (methyl-ammonium lead bromide) and the ferroelectric terpolymer (polyvinylidene fluoride trifluoroethylene-chlorofluoroethylene). A metal-insulator-metal type capacitor with the prepared composite exhibits the unique and photosensitive capacitive behavior at various light intensities in the visible light spectrum. The proposed photoreceptor mimics the spectral sensitivity curve of human photopic vision. The hybrid nanocomposite is stable in ambient air for 129 weeks, with no observable degradation of the composite due to the encapsulation of hybrid perovskites in the hydrophobic polymer. The functionality of the proposed photoreceptor to recognize handwritten digits (MNIST) dataset using an unsupervised trained spiking neural network with 72.05% recognition accuracy is demonstrated. This demonstration proves the potential of the proposed sensor for neuromorphic vision applications.

Dual functional inorganic CuSCN for efficient hole extraction and moisture sealing of MAPbI3 perovskite solar cells

Most high-performing organic-inorganic hybrid perovskite solar cells (PSC) are fabricated using expensive organic hole-transporting materials (HTM). The poor moisture- and thermal-stability of organic HTM is a significant factor contributing to...

(C3N2H5)3Sb2I9 and (C3N2H5)3Bi2I9 : Ferroelastic Lead-Free Hybrid Perovskite-Like Materials as the Potential Semiconducting Absorbers

We have synthesised and characterised novel organic-inorganic hybrid crystals: (C3N2H5)3Sb2I9 and (C3N2H5)3Bi2I9 (PSI and PBI). The thermal DSC, and TG analyses indicate four structural phase transitions (PTs) at 366.8/366.2, 274.6/275.4,...

Synthesis of CH3NH3PbI3 hybrid perovskite crystals for optoelectronic devices

This article is deals with the synthesis of hybrid organic-inorganic perovskite crystals. We present a brief review of the literature devoted to the synthesis of perovskite crystals. We have analyzed methods for the synthesis of perovskite crystals to select optimal conditions. Bulk perovskite crystals of CH3NH3PbI3 were synthesized. The resulting crystals were analyzed by X-ray phase analysis, which confirms the formation of tetragonal perovskite crystals and can be used to obtain thin films.