In 2018, our IT infrastructure was estimated to be responsible for 10% of electricity consumption and an amount of CO2 emission similar to that of the aviation industry. The COVID-19 outbreak exacerbated this further with an increase in internet traffic due to a push to working from home and increased consumption of streamed media content. This necessitates an urgent improvement to the energy efficiency of data transmission and processing. An important part of the energy consumption in IT systems is related to how the data is transmitted between various electronic components on chips and between different circuit boards. On processors, this is currently done using propagation of electrical signals along copper wires. An alternative to an on-chip information transmission via wires would be to encode the information into light. This would require miniaturization of optical modulators, which are currently limited in size to 10-100 um.
A way around the miniaturization limit of optical switches and the current interconnect paradigm is to implement devices and systems that would directly operate on excitons, bound electron-hole pairs that can form when a photon of light is absorbed by a semiconductor.
This project aimed to develop a demonstrator for recently shown room-temperature exciton transistors that can be used as nanoscale optical modulators. The main technical work carried out in the project was dedicated to the growth of synthetic nanostructures composed of 2D semiconductors using the metalorganic chemical vapor deposition method. Heterostructures hosting excitons have successfully been grown and were integrated into devices allowing them to be electrically controlled, demonstrating the feasibility of developing excitonic devices using scalable growth techniques.
