Electrically Tunable Valley-Light Emitting Diode (vLED) Based on CVD-Grown Monolayer WS2.
Electrically Tunable Valley-Light Emitting Diode (vLED) Based on CVD-Grown Monolayer WS2.
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DOI：
10.1021/acs.nanolett.5b04066
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发表时间：
2016-02
期刊：
影响因子：
10.8
通讯作者：
Weihuang Yang;J. Shang;Jianpu Wang;X. Shen;B. Cao;N. Peimyoo;C. Zou;Yu Chen;Yanlong Wang
中科院分区：
文献类型：
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作者：
Weihuang Yang;J. Shang;Jianpu Wang;X. Shen;B. Cao;N. Peimyoo;C. Zou;Yu Chen;Yanlong Wang
由于直接带隙和强自旋轨道耦合，单层过渡金属二硫属化物（TMD）表现出丰富的新物理和巨大的应用潜力。卓越的谷对比度和发光特性为这种二维 (2D) 半导体带来了谷电子学和发光二极管 (LED) 的光明前景。尽管在机械剥离的 TMD 小薄片中观察到了电致发光（EL），但考虑到实际应用，非常需要一种能够提供批量生产和高兼容性的策略。通过化学气相沉积 (CVD) 制备的大面积高质量样品是实现这一目标的完美候选者。在这里，我们报告了通过构建 p-i-n 异质结，首次演示了 CVD 生长的单层 WS2 的电可调手性 EL。整体EL的手性对比度高达81%，并且可以通过正向电流进行有效调制。基于 CVD WS2 的 Valley LED 的成功制造为开发非常规 2D 光电器件的大规模生产提供了许多机会。
Owing to direct band gap and strong spin-orbit coupling, monolayer transition-metal dichalcogenides (TMDs) exhibit rich new physics and great applicable potentials. The remarkable valley contrast and light emission promise such two-dimensional (2D) semiconductors a bright future of valleytronics and light-emitting diodes (LEDs). Though the electroluminescence (EL) has been observed in mechanically exfoliated small flakes of TMDs, considering real applications, a strategy that could offer mass-product and high compatibility is greatly demanded. Large-area and high-quality samples prepared by chemical vapor deposition (CVD) are perfect candidates toward such goal. Here, we report the first demonstration of electrically tunable chiral EL from CVD-grown monolayer WS2 by constructing a p-i-n heterojunction. The chirality contrast of the overall EL reaches as high as 81% and can be effectively modulated by forward current. The success of fabricating valley LEDs based on CVD WS2 opens up many opportunities for developing large-scale production of unconventional 2D optoelectronic devices.