Passivation of 1D@3D perovskite ferroelectric film with hydrophobic molecules for ferro-pyro-phototronic effect-based self-driven photodetector.

High-performance, self-driven photodetectors in commercial and public applications show promising prospects. The pyro-phototronic effect is a promising method for building these detectors, but limitations in interfacial contact conditions hinder the use of the ferro-pyro-phototronic effect. By modifying the surface of 1D@3D perovskite ferroelectric film with tetra-ethyl ammonium (TEAI) molecules, the interfacial defect density is reduced, resulting in a high-performance, stable photodetector.

Surface Passivation to Enhance the Interfacial Pyro-Phototronic Effect for Self-Powered Photodetection Based on Perovskite Single Crystals.

The interfacial pyro-phototronic effect (IPPE) presents a novel approach for improving the performance of self-powered photodetectors (PDs) based on metal halide perovskites (MHPs). The interfacial contact conditions within the Schottky junctions are crucial in facilitating the IPPE phenomenon. However, the fabrication of an ideal Schottky junction utilizing MHPs is a challenging endeavor.

A Self-Powered UV Photodetector With Ultrahigh Responsivity Based on 2D Perovskite Ferroelectric Films With Mixed Spacer Cations.

Self-powered photodetectors (PDs) have the advantages of no external power requirement, wireless operation, and long life. Spontaneous ferroelectric polarizations can significantly increase built-in electric field intensity, showing great potential in self-powered photodetection. Moreover, ferroelectrics possess pyroelectric and piezoelectric properties, beneficial for enhancing self-powered PDs.

Optical characteristics of bilayer decoupling MoS grown by the CVD method.

Study of exciton recombination process is of great significance for the optoelectronic device applications of two-dimensional transition metal chalcogenides (TMDCs). This research investigated the decoupling MoS structures by photoluminescence (PL) measurements. First, PL intensity of the bilayer MoS (BLM) is about twice of that of the single layer MoS (SLM) at low temperature, indicating no transition from direct bandgap to indirect bandgap for BLM due to the decrease of interlayer coupling which can be shown by Raman spectra.

Patterned 2D Ferroelectric Perovskite Single-Crystal Arrays for Self-Powered UV Photodetector Boosted by Combining Ferro-Pyro-Phototronic and Piezo-Phototronic Effects.

Metal halide perovskite ferroelectrics possess various physical characteristics such as piezoelectric and pyroelectric effects, which could broaden the application of perovskite ferroelectrics and enhance the optoelectronic performance. Therefore, it is promising to combine multiple effects to optimize the performance of the self-powered PDs. Herein, patterned 2D ferroelectric perovskite (PMA)PbCl microbelt arrays were demonstrated through a PDMS template-assisted antisolvent crystallization method.

Improved interface passivation by optimizing a polysilicon film under different hydrogen dilution in N-type TOPCon silicon solar cells.

The passivation properties of a polysilicon (poly-Si) thin film are the key for improving the photovoltaic performance of TOPCon silicon solar cells. In this work, we investigate the influence of the poly-Si microstructure on the interface passivation and photovoltaic performance in TOPCon solar cells. The poly-Si thin films are prepared from phosphorus-doped hydrogenated microcrystalline silicon (μc-Si:H) layers deposited plasma enhanced chemical vapor deposition (PECVD) under different hydrogen dilutions and recrystallized by high temperature post-deposition annealing.

Phonon and Exciton Properties between WS and MoS Layers via Inversion Heterostructure Engineering.

Recently, two-dimensional (2D) van der Waals heterostructures (vdWHs) have exhibited emergent electronic and optical properties due to their peculiar phonons and excitons, which lay the foundation for the development of photoelectronic devices. The dielectric environment plays an important role in the interlayer coupling of vdWHs. Here, we studied the interlayer and extra-layer dielectric effects on phonon and exciton properties in WS/MoS and MoS/WS vdWHs by Raman and photoluminescence (PL) spectroscopy.

Angle-resolved polarized Raman spectra of the basal and edge plane of MoS.

Angle-resolved polarized (ARP) Raman spectroscopy can be utilized to characterize the Raman modes of two-dimensional layered materials based on crystal symmetry or crystal orientation. In this paper, the polarization properties of and A modes on the basal plane and edge plane of high purity 2H-MoS bulk crystal grown by chemical vapor transport (CVT) method were investigated by ARP Raman spectroscopy. The I and II type ARP Raman spectroscopy with four kinds of polarization configurations: αY, αX, βY, and βX were used to explore the intensity dependence of and A modes at different planes on the polarization direction of incident/scattered light.

Ultrahigh, Ultrafast, and Self-Powered Visible-Near-Infrared Optical Position-Sensitive Detector Based on a CVD-Prepared Vertically Standing Few-Layer MoS/Si Heterojunction.

MoS, as a typical transition metal dichalcogenide, has attracted great interest because of its distinctive electronic, optical, and catalytic properties. However, its advantages of strong light absorption and fast intralayer mobility cannot be well developed in the usual reported monolayer/few-layer structures, which make the performances of MoS-based devices undesirable. Here, large-area, high-quality, and vertically oriented few-layer MoS (V-MoS) nanosheets are prepared by chemical vapor deposition and successfully transferred onto an Si substrate to form the V-MoS/Si heterojunction.

Large Lateral Photovoltage Observed in MoS Thickness-Modulated ITO/MoS/p-Si Heterojunctions.

Molybdenum disulfide (MoS), as a typical two-dimensional (2D) material, has attracted extensive attention in recent years because of its fascinating optical and electric properties. However, the applications of MoS have been mainly in photovoltaic devices, field-effect transistors, photodetectors, and gas sensors. Here, it is demonstrated that MoS can be found another important application in position sensitive detector (PSD) based on lateral photovoltaic effect (LPE) in it.

pH-Dependent Synthesis of Novel Structure-Controllable Polymer-Carbon NanoDots with High Acidophilic Luminescence and Super Carbon Dots Assembly for White Light-Emitting Diodes.

We use a pH-dependent solubility equilibrium to develop a one-pot aqueous synthesis of polymer carbon nanodots with novel structures. The chemical structure and photoluminescence (PL) were heavily influenced by the synthesis pH, with cross-linked polymer-carbon film (pH > 7), polymer carbon nanosheets (3 < pH < 7), and amorphous carbon structures (1 < pH < 3) achieved by altering the initial pH. Although pH-dependent structures frequently occur in typical semiconductors and supramolecular architectures involving metal, this is the first experimental work describing it in carbon nanodots.