EPSRC Engineering Fellowships for Growth: Narrow Band-gap Semiconductors for Integrated Sensing and Communications

半导体材料通过在无处不在的计算机和其他许多方面的应用，为当前经济提供了很大的动力。最常见的半导体是硅，约占世界市场的90%。然而，还有一些其他类型的半导体，它们提供了硅无法解决的功能，但也非常重要。这些例子包括：砷化镓，用于卫星接收器和移动电话的通信部件；基于磷化铟的材料，用于CD和DVD播放机的激光器以及沿光纤进行长距离通信；以氮化镓为基础的材料，用于制造白光发光二极管，这种二极管现在被用于一系列节能照明，甚至用于汽车前灯。所有这些材料都属于III-V族半导体，因为它们含有元素周期表中第3族和第5族元素的混合物。III-V半导体占电子工业剩余10%的大部分，全球每年价值约250亿英镑，并以每年约7%的速度增长。与硅工业不同，英国在制造基于这些材料的电子元件以及基于它们的系统方面占有重要地位，并且处于有利地位，可以从市场的快速增长中受益。锑化铟是III-V族半导体的另一个成员，锑化铟是铟和锑的化合物，其分子式为InSb。InSb有几个有趣的属性。电荷载体可以比其他任何一种载体运行得更快，并且需要更少的电压。因此，这种材料有可能制造出在非常高的频率下工作的组件，同时消耗很少的能量，因此，例如，使未来的移动设备能够下载大量数据，例如流式传输高清视频，而不会耗尽电池或堵塞网络。另一个应用是在不使用任何有害辐射的情况下，使成像能够探测非法爆炸物或火器。这些材料甚至可能会进入未来的计算机，使计算能力每两年翻一番，就像过去40年那样。这种材料的其他特性意味着我们可以制造用于热成像或有害气体检测的红外传感器，或者制造更高效的太阳能系统的光伏设备。这些特性的必然结果是，即使在室温下，热量也会导致材料“泄漏”电荷，因此目前唯一的商业应用是在高性能热成像系统中，该应用可以承受必须提供冷却到-200℃才能使其工作的成本。这种冷却需求以前被认为是基本的，然而Ashley和他的同事们已经证明，情况并非如此，在一些应用中，非冷却操作是可能的。这项研究将实现核心技术，使一系列不需要任何冷却就能工作的设备得以制造出来。这项技术包括能够在比人类头发丝小一千多倍的设备上制作功能，并使设备有效运行。它包括在设备上增加“纳米天线”，以提高它们对红外光的灵敏度。它还包括展示设备可以与硅集成的工作，以受益于硅工业大量投资带来的系统成本节约。这项研究的成功结果将是，英国的各个行业能够量化该技术提供的好处，并决定将其开发成产品。其中包括传感器制造商；移动通信领域有潜力的新公司；和可再生能源社区。

Semiconductor materials power much of the current economy, through their use in the ubiquitous computer and much else besides. The most common semiconductor is silicon, and this accounts for about 90% of the world market. There are some other types of semiconductor, however, that provide functions that silicon can't address but which are also very important. Examples of these include: gallium arsenide, which is used in satellite receivers and mobile phones for the communications parts; materials based on indium phosphide, which are used in lasers in CD and DVD players and for long distance communications along optical fibres; and materials based on gallium nitride, which are used to make the white light emitting diodes that are now being used for a range of energy efficient lighting and even in car headlights.All of these materials belong to a family known as III-V semiconductors, because they contain a mixture of elements from group 3 and group 5 of the periodic table. III-V semiconductors account for most of the remaining 10% of the electronics industry, and are worth approximately £25bn per year worldwide and growing at about 7%p.a. Unlike the silicon industry, the UK has a significant presence in the manufacture of electronic components based on these materials, as well as systems based upon them, and is in a good position to benefit from the rapid growth in the market.Another member of this III-V semiconductor family in indium antimonide, a compound of indium and antimony, which has the formula InSb. InSb has several interesting properties. Charge carriers can be made to go faster than in any other member of the family and take less voltage to do so. Consequently, this material has the potential to make components that will operate at very high frequencies whilst consuming very little power and so, for example, enable future mobile devices to download massive amounts of data, such as streaming high definition video, without draining the battery or clogging the network. Another application is to enable imaging for detection of illicit explosives or firearms, without use of any harmful radiation. These materials might even find their way into future computers to enable the doubling of computing power to continue every two years, as it has for the last forty years. Other properties of the material mean that we can make infrared sensors for thermal imaging or detection of harmful gases, or photovoltaic devices that would make much more efficient solar energy systems.A corollary of these properties is that heat can cause the materials to "leak" charge, even at room temperature, so currently the only commercial applications are in high performance thermal imaging systems, where the application can tolerate the cost of having to provide cooling to -200C to make them work. This need to cool was previously assumed to be fundamental, however Ashley and co-workers have shown that this is not necessarily the case, and that uncooled operation is possible in several applications. This research will put in place the core technology that would enable a range of devices to be made that will work without any cooling. This technology includes being able to make features on the devices that are more than one thousand times smaller than a human hair and still have the devices operating effectively. It includes the addition of "nano-antennas" to the devices to improve their sensitivity to infrared light by orders of magnitude. It also includes work to show that the devices could be integrated with silicon, to benefit from the system cost savings derived from the massive investment in the silicon industry. The successful outcome of this research would be that various industries in the UK are able to quantify the benefits that the technology offers and make decisions to develop it into products. These would include the sensor manufacturers; prospective new companies in the mobile communications field; and renewable energy community.