単一のダイケトピロピロロール交差点での共振輸送
Yaping Zang1, Suman Ray2, E-Dean Fung1
1Department of Applied Physics and Applied Mathematics , Columbia University , New York , New York 10027 , United States.
Journal of the American Chemical Society
|October 4, 2018
まとめ
ディケトピロピロロールオリゴーマーには,単一分子の電荷輸送が効率的です. 高いバイアスでは,共振輸送が観察され,分子電子学の可能性が示されます.
科学分野:
- 材料科学
- 分子電子
- 有機半導体
背景:
- ディケトピロピロロール (DPP) オリゴーマーが有望な有機半導体である.
- 単一分子装置における電荷輸送の理解は,分子電子学にとって極めて重要です.
- 以前の研究では DPP の性質を調査しましたが,長距離輸送のメカニズムはさらなる調査を必要としています.
研究 の 目的:
- 単一分子輸送特性を研究するために,異なる長さのディケトピロピロロールオリゴーマー (DPP n, n = 1-4)
- 異なるバイアス電圧での輸送メカニズムを解明する.
- 効率的な長距離貨物輸送のためのDPPデリバティブの可能性を評価する.
主な方法:
- DPP オリゴーマー (1-5 nm 長さ) の単分子伝導率の実験測定
- 変性バイアス電圧は,探査機輸送方式に適用されます.
- 密度関数理論 (DFT) ベースの計算で,輸送特性をモデル化します.
主要な成果:
- 低バイアスでは,伝導性は長さとともに指数分解し,非共振輸送の典型です.
- 高バイアスで,非常に高い伝導率 (約. 10^-2 G0) と電流 (> 0. 1 μA) は,すべてのDPPオリゴマーで観察されました.
- DFTの計算は,分散されたDPPのバックボーンによる高バイアスの共鳴輸送メカニズムをサポートします.
結論:
- DPPオリゴーマーには,効率的な長距離電荷輸送能力があることが示されています.
- 高いバイアスで共振輸送への移行は,高い伝導率に責任があります.
- DPPデリバティブは,単分子電子機器での応用において有望である.
関連する概念動画
02:52Resonance
65.6K
The Lewis structure of a nitrite anion (NO2−) may actually be drawn in two different ways, distinguished by the locations of the N-O and N=O bonds.
65.6K
01:11P-N junction
1.2K
A p-n junction is formed when p-type and n-type semiconductor materials are joined together. At the interface of the p-n junction, holes from the p-side and electrons from the n-side begin to diffuse into the opposite sides due to the concentration gradient. This diffusion of carriers leads to a region around the junction where there are no free charge carriers, known as the depletion region. The charge density within the depletion region for the n-side and p-side can be described by the...
1.2K
01:19Facilitated Transport
148.7K
The chemical and physical properties of plasma membranes cause them to be selectively permeable. Since plasma membranes have both hydrophobic and hydrophilic regions, substances need to be able to transverse both regions. The hydrophobic area of membranes repels substances such as charged ions. Therefore, such substances need special membrane proteins to cross a membrane successfully. In facilitated transport, also known as facilitated diffusion, molecules and ions travel across a...
148.7K
01:47Primary Active Transport
198.9K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction...
198.9K
01:55Secondary Active Transport
137.9K
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
137.9K
02:22Regulated mRNA Transport
7.0K
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
7.0K