Synthesis of SOT-OH as a building block for the synthesis of new dimeric and trimeric Spiro-OMeTAD Materials
Namrata Pant a, Michele Cariello a, Alexander Harkiss a, Frances Tracey a, Joseph Cameron a, Peter Skabara a, Peter Holliman b, Pablo Docampo a, Graeme Cooke a
a School of Chemistry, University of Glasgow, University Pl, G12 8QQ, Glasgow, UK
b College of Engineering, Bay Campus, Swansea University, Swansea, SA1 8EN, UK
International Conference on Hybrid and Organic Photovoltaics
Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV22)
València, Spain, 2022 May 19th - 25th
Organizers: Pablo Docampo, Eva Unger and Elizabeth Gibson
Oral, Namrata Pant, presentation 203
Publication date: 20th April 2022

Charge transporting layers are the pillars of high performing perovskite solar cells, facilitating efficient charge extraction and transport across the device. The right choice of these materials, complementing the energetic alignments of the adjacent perovskite stacks and the electrodes plays a significant role in enhancing the device efficiency. Spiro-OMeTAD is by far one of the most popular and successful charge (hole) transporting materials used in n-i-p perovskite-based devices. However, its several intrinsic drawbacks including its long-term stability, low conductivity, and hole-mobility, in addition to the high cost of synthesis and purification do not deem it to be the most favourable hole transporting material. In the present work we have devised a novel synthetic route to prepare unsymmetric Spiro-OMeTAD derivatives. We report the synthesis of a mono-demethylated Spiro-OMeTAD derivative, SOT-OH, utilizing two different synthetic protocols and show two new derivatives, a dimer (SOT-D) and a trimer (SOT-T) as exemplars. The materials are characterised for their optical, structural and electrical properties, and we show that they are more conductive than the reference Spiro-OMeTAD. Further, we fabricate the perovskite solar cell devices, and observe that these materials deliver comparable performance when used in place of the benchmark sublimed Spiro-OMeTAD.

We thank the EPSRC for funding (GC and AHH EP/P030106/1, PJH EP/P030068/1 and PD EP/T010568/1). We also thank Dr Logan Mackay of the Scottish Instrumentation and Resource Centre for Advanced Mass Spectrometry (University of Edinburgh; Edinburgh, Scotland, UK), for running some of the HRMS.

We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info