Karl Jonas Riisnaes, The 1966 PhD Scholar

Postgraduate Researcher, EPSRC Centre for Doctoral Training in Metamaterials (XM2)

I am writing to give you an update on my research which is kindly supported by the 1966 PhD scholarship. When I last saw you in May 2019, for our tour of the Physics department's clean room facilities, I had been part of the metamaterials research for 8 months. Since then my project has developed significantly and I've had to learn to use a significant amount of equipment and software used in fabrication and characterisation of semiconducting devices to support my research towards demonstrating an electrically driven hybrid graphene and perovskite laser. Before going more in to detail on my progress I would like to give a brief project overview:

Project overview

- Establish and investigate the viability of transportation and storage of Organo-Halide Perovskite Crystals from our collaborators in Italy to our facilities in Exeter

- Examine methods of device fabrication based on Organo-Halide Perovskite Crystals

- Crystal exfoliation and transfer to Silicon substrates to obtain few layer crystals for device manufacturing

- Electrical contact deposition on crystal though orthogonal electron beam lithography

- Fabrication and measurement of perovskite based Photo transistor

- Fabrication of perovskite based light emitting diode

- Achieve electrically induced lasing

Research progress to date

Organo-Halide Perovskite crystals are a research-field in its infancy, however its potential is huge. The crystals are easy and incredibly cheap to make and contains materials which are readily available and inexpensive. This makes perovskite an attractive alternative to today's often hard to obtain and expensive to process materials. A major problem with perovskites is the difficulty of making devices using established high precision methods. Over the last 6 months I have developed a novel method creating devices with organo-halide perovskites using electron beam lithography allowing nanometer size precision. These devices which are photo transistors, are sensitive to light, micro meter in size and have features in the nanometer scale. Among other interesting features, the devices opto-electronic response is the fastest ever measured in our facilities. The results from these first devices will be published in a journal the coming months.

Practical experience gained

The research undertaken has required me to develop skills in using fabrication equipment; one example is our electron beam evaporator used in high precision metal deposition. A major part of the practical experience has also come from the need of using the optical and electrical characterisation equipment in conjunction with data acquisition software to study the opto-electronic response of the perovskite based photo transistors developed.

Thank you

Finally I would like to express my gratitude and appreciation for the continued support of this scholarship. It provides me with the opportunity to focus solely on my research enabling me to develop as a researcher to the best of my ability.

I look very much forward to keep you updated on my progress.