Physical Sensors & Devices

Efficient carrier selective contacts are key to electronic devices based on silicon including sensors, microelectromechanical systems, field effect transistors and photovoltaics. We explore substoichiometric molybdenum trioxide (MoOx, x<3) as a dopant-free, hole-selective contact for silicon. As a proof of principle, we demonstrate a silicon solar cell with a MoOx hole contact delivering a high open-circuit voltage of 711 mV and a power conversion efficiency of 18.8%. Due to the wide band gap of MoOx, we observe a substantial gain in photocurrent of 1.9 mA/cm2 in the ultraviolet...

Optogenetics techniques that have been developed over the previous decade allow cell-type specific optical stimulation of neurons in-vivo. However, it remains a challenge to perform simultaneous electrical recording while providing optical stimulation due to photoelectric artifact generated at the microelectrode recording sites. This project aims to address this challenge by developing bio- compatible microelectrode arrays with optically transparent recording sites. Current devices are optimized for performing electrocorticography (ECoG) experiments and use Indium-Tin Oxide (ITO, a...

The project amis at using Near Field Electrospinnin to fabricate top gate graphene transistor that is capable to pattern the source and drain electrodes through a self-alignment process, and the long range goals is to direct writing graphene transistors onto flexible and transparent substrate for low cost circuit applications, say RF mixer. As the conventional top gated device fabrication process often introduces the deposition of thin inorganic dielectric onto graphene layer with extra surface functionalizations, leading to an undesired damage of graphene lattice, or a non-ideal...

Sensing in harsh environment, especially high temperature environment, is drawing more attention, with potential applications in energy sector. The motivations are that enhanced (pressure, temperature, chemical) sensing will allow more efficient operation, enabling condition- based monitoring and reducing unwanted emission. State-of-the-art sensing technology remains limited, either not capable of long-term online monitoring under high temperature due to materials failure or, occupying too much space. We propose to adapt MEMS fabrication process and concepts to our proposed research...