High‐Performance n‐ and p‐Type Field‐Effect Transistors Based on Hybridly Surface‐Passivated Colloidal PbS Nanosheets

Abstract

Colloidally synthesized nanomaterials are among the promising candidates for future electronic devices due to their simplicity and the inexpensiveness of their production. Specifically, colloidal nanosheets are of great interest since they are conveniently producible through the colloidal approach while having the advantages of two-dimensionality. In order to employ these materials, according transistor behavior should be adjustable and of high performance. It is shown that the transistor performance of colloidal lead sulfide nanosheets is tunable by altering the surface passivation, the contact metal, or by exposing them to air. It is found that adding halide ions to the synthesis leads to an improvement of the conductivity, the fieldeffect mobility, and the on/off ratio of these transistors by passivating their surface defects. Superior n-type behavior with a field-effect mobility of 248 cm 2 V −1 s −1 and an on/off ratio of 4 × 10 6 is achieved. The conductivity of these stripes can be changed from n-type to p-type by altering the contact metal and by adding oxygen to the working environment. As a possible solution for the post-Moore era, realizing new high-quality semiconductors such as colloidal materials is crucial. In this respect, the results can provide new insights which helps to accelerate their optimization for potential applications.

Function Follows Form: From Semiconducting to Metallic toward Superconducting PbS Nanowires by Faceting the Crystal

“…[ 49,50 ] These measurements (shown in Figures S10c and S11 in the Supporting Information) reveal that the Cl content on the surface of the zigzag wires (15%) is lower compared to the straight nanostripes (20%) and especially compared to the previously studied PbS nanosheets (30–60%). [ 51 ] In addition, the HAADF–XEDS measurements show a lower Cl content in the whole crystal of the zigzag wires compared to the straight stripes (Figure S12, Supporting Information). Therefore, it can be concluded that the performed synthesis fulfils this requirement and preserves metallic behavior of the wires by reducing the Cl content on the surface of the crystal.…”

2D Materials Based on Main Group Element Compounds: Phases, Synthesis, Characterization, and Applications

“…[ 208 ] These rock‐salt PbS nanosheets showed high performance in FET applications, which can be either n‐ or p‐type depending on the surface defects introduced. [ 209 ] Recently, this group also reported the spintronics of rock‐salt PbS with an unusual selection mechanism of carrier excitation, which can be tuned by the gate voltage and thickness of the materials. [ 210 ] Apparent quantum confinement was observed when the thickness of PbS was reduced from 6 to 2 nm.…”

Two-Dimensional Pnictogen for Field-Effect Transistors

“…Exfoliated 2D phosphorene nanosheets without encapsulation are found to chemically degrade upon exposure to ambient conditions urgently [137]. Passivation is a prominent approach to decrease surface degradation, which not only decreases the surface roughness but also avoids the formation of chemisorbed species [157–162]. Wood et al investigated how exfoliated black phosphorus degrades to oxygenated phosphorus compounds in the ambient condition through a systematical suite of microscopy and spectroscopy techniques [36].…”