Next generation narrow band-gap semiconductor ballistic nanosensors for high resolution room temperature magnetometry and photodetection.
Abstract:
The drive towards next generation room temperature nanoelectronic and optoelectronic devices is extremely active across a range of material systems. Of particular interest are nanosensors that can deliver high sensitivity to an applied external perturbation (such as magnetic, electric or optical field) together with high spatial resolution (<100 nm) to create a range of new imaging modalities. High mobility thin films and 2D electron gases (2DEGs) are desirable for achieving high sensitivity. Indium antimonide (InSb) is a narrow band-gap semiconductor with the highest room temperature mobility of any traditional material system (up to 50 x greater than Si and 15 x greater than GaAs) with considerable promise for nanoelectronic applications. Nevertheless, InSb-based nanodevices suffer from parasitic current leakage through the buffer layer that is accentuated by nanofabrication. In this talk I will discuss research carried out at Imperial College on the application of high mobility InSb 2DEGs. I will focus on the recent technological advancements that have led to the operation and observation of ballistic transport in InSb 2DEG nanodevices at 300 K, demonstrating high quality electronic properties preserved at the nanoscale. I will discuss the detection properties of InSb 2DEG nano-Hall probes and compare their performance to competitive sensors technologies. Finally I will discuss the potential for utilising such ballistic devices to develop novel functionality photodetectors and charge sensors.