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使用，为当前的经济提供了很大动力。最常见的半导体是硅，约占全球市场的90%。然而，还有一些其他类型的半导体提供了硅无法解决的功能，但这些功能也非常重要。其中包括：用于卫星接收器和移动电话通信部件的砷化镓；基于磷化铟的材料，用于CD和DVD播放机的激光和沿光纤的长距离通信；基于氮化镓的材料，用于制造白光发光二极管，现在用于一系列节能照明，甚至用于汽车前照灯。所有这些材料都属于被称为III-V半导体的家族，因为它们包含元素周期表中第3族和第5族元素的混合。III-V半导体占电子行业剩余10%的大部分，每年全球价值约250亿GB，并以每年约7%的速度增长。与硅行业不同，英国在基于这些材料的电子元件以及基于这些材料的系统的制造中占有重要地位，并处于有利地位，可以从市场的快速增长中受益。铟-V半导体家族的另一个成员是铟锑，这是一种铟和锑的化合物，其公式为InSb。InSb有几个有趣的属性。电荷载体可以比家族中的任何其他成员走得更快，而且需要更少的电压。因此，这种材料有可能制造出在非常高的频率下运行的组件，同时消耗的电力非常少，因此，例如，使未来的移动设备能够下载大量数据，例如流传输高清晰度视频，而不会耗尽电池或堵塞网络。另一个应用是使成像能够在不使用任何有害辐射的情况下检测非法爆炸物或枪支。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年一样。这种材料的其他特性意味着我们可以制造用于热成像或检测有害气体的红外传感器，或者制造光伏设备，从而使太阳能系统变得更加高效。这些特性的推论是，即使在室温下，热也会导致材料“泄漏”电荷，因此目前唯一的商业应用是高性能热成像系统，在这种应用中，必须提供零下200摄氏度的冷却才能使其工作，这一应用程序可以容忍成本。这种冷却的需要以前被认为是基本的，然而Ashley和他的同事已经证明了不一定是这种情况，并且在几个应用中非冷却操作是可能的。这项研究将建立核心技术，使一系列设备能够在没有任何冷却的情况下工作。这项技术包括能够在比人类头发小一千多倍的设备上制造功能，并仍然使设备有效运行。它包括在设备上添加“纳米天线”，以提高其对红外光的敏感度数量级。它还包括证明这些设备可以与硅集成的工作，以受益于在硅行业的大规模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这项技术提供的好处，并做出决定将其开发成产品。这将包括传感器制造商；移动通信领域潜在的新公司；以及可再生能源社区。

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.