What was the focus of your PhD research? Can you explain it to a non-scientific audience?

The focus was to study the theory of heat transport in organic polymers, a class of sustainable materials that could be successfully employed to generate electricity from heat.

Can you briefly summarize the main findings or contributions of your research? You can give us some examples.

I studied how doping affects thermal transport in PEDOT:PSS, one of the most promising organic thermoelectric materials, uncovering its underlying mechanisms.

Why do you think your research is important, and how could it impact your field or society?

Fabricating thermoelectric devices with sustainable, biocompatible and non-toxic materials will not only reduce costs, but it will also have a positive impact on our environment and public health.

What was one of the most challenging aspects of your PhD journey, and how did you overcome it?

I come from a fairly distant field of study: electrical engineering. This means that I knew very little about several key physics and chemistry topics at the beginning of my PhD. To overcome this obstacle, I chose the only possible option: autonomous study from both books and online sources.

Why did you end up at ICMAB? And what do you think you will miss the most from this institute?

My former Professor at the University of Cagliari (Claudio Melis) notified me about this position at ICMAB and I immediately liked the idea, so I applied and eventually got it. I’ll definitely miss my colleagues.

What’s next for you after completing your PhD? Do you have any upcoming projects or goals?

I have already joined Eurecat as a Postdoc, where I will be working on AI driven material discovery.

How has completing this PhD changed you, either professionally or personally?

I have learned a lot, not only about my research topics, but also about how to handle complex projects from start to finish. I have also learned more about myself: what I can and cannot do, and how to deal with the stress.

What advice would you give to someone just starting their PhD journey?

Technical advice: start writing your thesis as soon as possible, and always be on the lookout for new literature that’s relevant to your research. Personal advice: you will encounter difficulties that seem insurmountable, but just take a step back and breathe.

Take your time, face each challenge with patience and always be ready to learn new things.

Why did you become a scientist? Which have been your role models that inspired you to pursue a PhD?

I have always wanted to take part in the human effort that is technology. It is about understanding the world around us and harnessing its physical laws to make our lives easier and more meaningful. There isn’t one role model, but rather several people such as my father, my high school physics teacher and others.

Who or what helped you the most during your PhD journey, and is there anyone you'd like to thank?

I would say my supervisor Riccardo Rurali has helped me in many aspects, including the technical and personal one, so a big thank you goes to him. I’m also extremely grateful to Ana, who has become my wife during these PhD years and has supported me throughout this journey. I’d like to thank my family and friends both in Sardinia and Croatia, my colleagues at ICMAB and in the HORATES network, and my friends at Cor Trobada here in Barcelona.

Abstract

This thesis presents an investigation of the lattice thermal conductivity of amorphous poly(3,4-ethylenedioxythiophene) (PEDOT) and PEDOT:poly(styrenesulphonate) (PSS), focusing on the effects of bipolarons on morphology and thermal transport, as well as addressing the individual contribution of PSS. It also focuses on the thermal conductivity of doped crystalline PEDOT nanofibers to assess the potential for heat transfer suppression by exploiting anisotropic conduction properties. The key topic of thermal stability is covered with a study on the Lewis pair doping approach, which provides efficient doping across various organic semiconductors, enabling high electrical conductivity while offering exceptional stability. Furthermore, this thesis addresses the doping efficiency of poly(benzodifurandione) (PBFDO), a promising n-type organic semiconductor with significant potential for thermoelectric applications. By investigating the thermodynamics of the doping reaction in this polymer, this work aims to minimize dopant concentration without compromising doping performance, advancing its application in thermoelectric devices.

Supervisors

• Riccardo Rurali, ICMAB-CSIC, Spain

PhD Comitte

• President: Marta González Silveira, UAB, Spain
• Secretary: Jordi Faraudo, ICMAB-CSIC, Spain
• Vocal: Alessandro Troisi, University of Liverpool, UK