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. It's been a strange year so far and quite a few routines and procedures have had to change both in private and work life. When we last spoke, working in the lab alongside my colleges and friends was a daily routine - now I am just about to be allowed back in to the labs, but under strict regimes and mostly with single occupancy. The cleanroom I gave you a tour of when you visited last year is under such a regime so to make progress requires much more planning and collaboration with the people who have access. My work is hence carried out remotely and some of the focus has shifted over to more simulation based research to support future work in the labs.

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 by demonstrating an electrically driven hybrid graphene and perovskite laser.

Research progress to date

When I last wrote to you I had just about gathered enough data to make a publication on my novel method of making photo transistors with 2D hybrid perovskite crystals using electron beam lithography. Since then, we have worked together with a group of theorists led by Prof. Steven Hepplestone. They have helped us describe the physics at the interfaces between the crystal and electrode produced by our novel method of fabrication. This work has culminated in a paper we have submitted which is now with reviewers.

Recently I presented some of my work on finding chemically orthogonal processing solvents for Organo-Halide Perovskite Crystals at the annual conference (Frontiers in Optics) of the Optical Society of America. A journal publication associated with this presentation should be made available in the coming weeks.

Towards Christmas I am hoping to be more present in the laboratory to bring the research further. For now, several people in my research group are involved in the work towards producing an LED based on this type of perovskite. This work is using everything we have learned about processing these crystals so far. The work towards LEDs will require us to make use of several other techniques as well which we are now exploring.

Practical experience gained

Over the last six months I have had to learn to work remotely which has meant often instructing others to do work in my place. This has challenged me to reassess my communication skills which I believe has increased my abilities to communicate its often complex content. Further, the writing of two research papers for journal publication has taught me a lot in terms of my writing skills, but also led me to a much deeper understanding of the physics involved.

Thank you

Finally I would like to express my gratitude and appreciation for the continued support of this scholarship. As mentioned in previous updates, it provides me with the opportunity to focus on my research which I believe is immensely beneficial to its progress. As soon as the papers are published I will update you.