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.

Recent Progress in Flexible Multiferroics

A great deal of interest has grown in both academia and industry toward flexible multiferroics in the recent years. The coupling of ferromagnetic properties with ferroelectric properties in multiferroic materials opens up many opportunities in applications such as magnetoelectric random access memories, magnetic field sensors, and energy harvesters. Multiferroic materials on a flexible platform bring an exciting opportunity for the next generation of consumer electronics owing to their unique characteristics of wearability, portability, and weight reduction. However, the fabrication of flexible multiferroic devices is still a great challenge due to various technical difficulties, including the requirement of high growth temperature of the oxide-based multiferroic materials, their lattice mismatch with the flexible substrates, and the brittleness of the functional layers. In this review article, we will discuss different methods of fabricating flexible or even freestanding oxide films to achieve flexible electronics. This article will address the benefits and challenges of each synthesis method in terms of interlayer interactions and growth parameters. Furthermore, the article will include an account of the possible bending limits of different flexible substrates without degrading the properties of the functional layer. Finally, we will address the challenges, opportunities, and future research directions in flexible multiferroics.

Tailoring Molecular Weight of Polymer Additives for Organic Semiconductors

A binary system comprising both an organic semiconductor and a polymer additive has attracted extensive research interests due to great potential for high-performance, solution-proccessable electronic devices on flexible substrates. The...

Photocatalytic degradation of methylene blue (MB) with Cu1-ZnO single atom catalysts on graphene-coated flexible substrates

Defects can predominantly dictate properties of oxide materials, in particular, the photocatalytic and electrical properties. By implanting the defects of metallic element, Cu atom doped ZnO (Cu1-ZnO) supported by graphene-coated...

Arylenevinylene Oligomer-Based Heterostructures on Flexible AZO Electrodes

We investigated the optical and electrical properties of flexible single and bi-layer organic heterostructures prepared by vacuum evaporation with a p-type layer of arylenevinylene oligomers, based on carbazole, 3,3′ bis(N hexylcarbazole)vinylbenzene = L13, or triphenylamine, 1,4 bis [4 (N,N’ diphenylamino)phenylvinyl] benzene = L78, and an n-type layer of 5,10,15,20-tetra(4-pyrydil)21H,23H-porphyne = TPyP. Transparent conductor films of Al-doped ZnO (AZO) with high transparency, >90% for wavelengths >400 nm, and low resistivity, between 6.9 × 10−4 Ωcm and 23 × 10−4 Ωcm, were deposited by pulsed laser deposition on flexible substrates of polyethylene terephthalate (PET). The properties of the heterostructures based on oligomers and zinc phthalocyanine (ZnPc) were compared, emphasizing the effect of the surface morphology. The measurements revealed a good absorption in the visible range of the PET/AZO/arylenevinylene oligomer/TPyP heterostructures and a typical injection contact behavior with linear (ZnPc, L78) or non-linear (L13) J-V characteristics in the dark, at voltages <0.4 V. The heterostructure PET/AZO/L78/TPyP/Al showed a current density of ~1 mA/cm2 at a voltage of 0.3 V. The correlation between the roughness exponent, evaluated from the height-height correlation function, grain shape, and electrical behavior was analyzed. Consequently, the oligomer based on triphenylamine could be a promising replacement of donor ZnPc in flexible electronic applications.

High performance p-channel transistors on flexible substrate using direct roll transfer stamping

lexible electronics with high-performance devices is crucial for transformative advances in several emerging and traditional applications. To address this need, herein we present p-type silicon (Si) nanoribbons (NR)-based high-performance field-effect transistors (FETs) developed using innovative Direct Roll Transfer Stamping (DRTS) process. First, ultrathin Si NRs (~70 nm) are obtained from silicon on insulator (SOI) wafers using conventional top-down method, and then DRTS method is employed to directly place the NRs onto flexible substrates at room temperature (RT). The NRFETs are then developed following RT fabrication process which include deposition of high-quality SiNx dielectric. The fabricated p-channel transistors demonstrate high linear mobility ~100±10 cm2/Vs, current on/off ratio >10^4, and low gate leakage (<1nA). Further, the transistors showed robust device performance under mechanical bending and at wide temperature range (15 to 90 °C), showing excellent potential for futuristic high-performance flexible electronic devices/circuits.