Electrical Characterization of Individual Cesium Lead Halide Perovskite Nanowires Using Conductive AFM

Abstract

Perovskite nanostructures have attracted much attention in recent years due to their suitability for a variety of applications such as photovoltaics, light‐emitting diodes (LEDs), nanometer‐size lasing, and more. These uses rely on the conductive properties of these nanostructures. However, electrical characterization of individual, thin perovskite nanowires has not yet been reported. Here, conductive atomic force microscopy characterization of individual cesium lead halide nanowires is presented. Clear differences are observed in the conductivity of nanowires containing only bromide and nanowires containing a mixture of bromide and iodide. The differences are attributed to a higher density of crystalline defects, deeper trap states, and higher inherent conductivity for nanowires with mixed bromide–iodide content.

Surface Charge Alteration in Carbon Dots Governs the Interfacial Electron Transfer and Transport

“…Many reports evince that the conductivity of a molecule can be tuned by variation in its size, surface functionalization, HOMO–LUMO gap, barrier height, local DOS, carrier concentration, contact properties, molecular bonding, etc. − These parameters can be interpreted by measuring their I – V characteristic curves. Figure a,b present the I – V spectra of different CDs in the presence and absence of MD in both H 2 O–EtOH and the CTAB medium, respectively.…”

n-Type Doping of Triethylenetetramine on Single-Wall Carbon Nanotubes for Transparent Conducting Cathodes

“…Bundles of mixed (metallic and semiconducting) SWCNTs were deposited on a freshly cleaved mica substrate by drop-casting to form a sparse network. Atop part of the network, a stationary gold electrode was evaporated by stencil lithography, as described previously. ,− An optical microscope image, presented in Figure b, shows the evaporated gold electrode and the exposed mica, which was shielded by the mask during the stencil lithography evaporation. An electrode (∼25 nm apparent height) with a sharp edge at the gold border was obtained with SWCNTs protruding beneath it (Figure c and cross section in the inset).…”

Anomalous NH3-Induced Resistance Enhancement in Halide Perovskite MAPbI3 Film and Gas Sensing Performance

“…Then, we recorded the evolution of the local I – V characteristic of MAPbI 3 grains when exposed to NH 3 gas, by positioning a c-AFM tip at the labeled white triangle region (Figure c). Before blowing NH 3 gas, one can see that a quiet weak current is detected even at a high-bias regime (4.5 V), which is correlated to the number of charge traps in the measured grains . Surprisingly, the current value rises rapidly upon injecting NH 3 gas, and then recovers to an initial value after removal of NH 3 .…”

“…Before blowing NH 3 gas, one can see that a quiet weak current is detected even at a high-bias regime (4.5 V), which is correlated to the number of charge traps in the measured grains. 28 Surprisingly, the current value rises rapidly upon injecting NH 3 gas, and then recovers to an initial value after removal of NH 3 . To better observe this NH 3 -induced current change, we plotted the current overtime at a bias of 4.5 V (Figure 2d).…”