Abstract:
During the last few years graphene has emerged as a potential candidate for electronics and optoelectronics applications due to its several salient features. Graphene is a smart material that responds to any physical change in its surrounding environment. Graphene has a very low intrinsic electronic noise and it can detect even a single gas molecule in its proximity. This property of graphene makes is a suitable and promising candidate to detect a large variety of organic/inorganic chemicals and gases. Typical solid state gas sensors usually requires high operating temperature and they cannot detect very low concentrations of gases efficiently due to intrinsic noise caused by thermal motion of charge carriers at high temperatures. They also have low resolution and stability issues of their constituent materials (such as electrolytes, electrodes, and sensing material itself) in harsh environments. It accelerates the need of development of robust, highly sensitive and efficient gas sensor with low operating temperature. Graphene and its derivatives could be a prospective replacement of these solid-state sensors due to their better electronic attributes for moderate temperature applications. The presence of extremely low intrinsic noise in graphene makes it highly suitable to detect a very low concentration of organic/inorganic compounds (even a single molecule ca be detected with graphene). In this article, we simulated a novel graphene nanoribbon based field effect transistor (FET) and used it to detect propane and butane gases. These are flammable household/industrial gases that must be detected to avoid serious accidents. The effects of atmospheric oxygen and humidity have also been studied by mixing oxygen and water molecules with desired target gases (propane and butane). The change in source-to-drain current of FET in the proximity of the target gases has been used as a detection signal. Our simulated FET device showed a noticeable change in density of states and IV-characteristics in the presence of target gas molecules. Nanoscale simulations of FET based gas sensor have been done in Quantumwise Atomistix Toolkit (ATK). ATK is a commercially available nanoscale semiconductor device simulator that is used to model a large variety of nanoscale devices. Our proposed device can be converted into a physical device to get a low cost and small sized integrated gas sensor.
摘要:
在过去的几年中,石墨烯由于其几个显着的特征而成为电子和光电子学应用的潜在候选者。石墨烯是一种智能材料,可响应周围环境中的任何物理变化。石墨烯具有非常低的固有电子噪声,甚至可以检测其附近的单个气体分子。石墨烯的这种性质是检测各种有机/无机化学品和气体的合适且有前途的候选物。典型的固态气体传感器通常需要高工作温度,并且由于在高温下由电荷载流子的热运动引起的固有噪声,它们不能有效地检测非常低的气体浓度。它们的组成材料(例如电解质,电极,和传感材料本身)在恶劣的环境中。它加速了健壮发展的需要,高灵敏度和低工作温度的高效气体传感器。石墨烯及其衍生物可能是这些固态传感器的潜在替代品,因为它们在中等温度应用中具有更好的电子属性。石墨烯中存在极低的固有噪声使得其非常适合于检测极低浓度的有机/无机化合物(甚至可以用石墨烯检测到单个分子)。在这篇文章中,我们模拟了一种基于石墨烯纳米带的新型场效应晶体管(FET),并将其用于检测丙烷和丁烷气体。这些是易燃的家用/工业气体,必须检测以避免严重事故。还通过将氧气和水分子与期望的目标气体(丙烷和丁烷)混合来研究大气氧气和湿度的影响。在目标气体附近的FET的源极-漏极电流的变化已被用作检测信号。在存在目标气体分子的情况下,我们的模拟FET器件显示出状态密度和IV特性的显着变化。基于FET的气体传感器的纳米级模拟已经在QuantumwiseAtomistix工具包(ATK)中完成。ATK是一种市售的纳米级半导体器件模拟器,用于对各种纳米级器件进行建模。我们提出的设备可以转换为物理设备,以获得低成本和小尺寸的集成气体传感器。