"IEEE-OSC" - Interface-engineered and energy-efficient organic solar cells based on porphyrin small molecules

05 September 2018

Project coordinator:

Xiaobin Peng

South China University of Technology


Project partners:

Paulo Barbeitas Miranda

University of Sao Paulo


Sai Santosh Kumar Raavi

Indian Institute of Technology Hyderabad


Funding agencies:

CNPq (Brazil), DST (India), NSFC (China)


Thin film organic solar cells (OSCs) hold promise for fabricating lightweight and flexible devices via the low-cost and high-throughput roll-to-roll production process. This has triggered extensive research efforts around the world towards understanding and improving the photo-conversion efficiency (PCE) of OSCs. Improving the PCE depends on a solid knowledge and innovation of the design and synthesis of novel molecules with improved functionalities, ability to control active layer morphology that affects the charge transport and extraction from the devices, as well as, controlling the overall interface energetics in these multilayer, thin film devices. In this proposal project team will combine the available expertise in (i) the synthesis of new porphyrin molecules as donors, (ii) development of new interlayer materials (ETLs and HTLs), and (iii) understanding the device physics employing various optical and electrical techniques for measuring the charge photogeneration, recombination and transport, to develop highly efficient and stable OSCs based on porphyrin derivatives. The Chinese team (main PI) has proven expertise in synthesis of π- conjugated electron donor-acceptor (D-A) porphyrin molecules and have achieved power conversion efficiencies higher than 9%. They will also participate in the device preparation and characterization, and in the tuning of morphology and interfaces, which will provide feedback and understanding for the iterative materials development with the aim of achieving higher performance OSC materials. In addition, the Indian team has specific expertise on: (a) employing various transient optical spectroscopy tools to characterize the new molecules and (b) developing interlayer materials like doped metal oxides as ETLs and conducting polymers-metal oxide composite as HTLs, and “green” quantum dots (QDs) like Copper Indium Sulphide (CIS) QDs that can be used as additives to the active layer. The Brazilian team will use its expertise on interface specific spectroscopy tools and various electrical transport measuring techniques (photoinduced charge extraction by linearly increasing voltage, transient absorption and transient photoconductivity, etc.) to study charge transport and interfacial molecular orientation and electric fields. These device properties will be used by the Chinese and Indian team to develop new materials and architectures that would improve the device PCE. The synergy among the expertise and materials/techniques available on the three teams will significantly increase our chance of success to achieve OSCs with an efficiency of 15% or 10% but with a lifetime of 1000 h under a continuous AM1.5 simulated solar illumination. The breakthroughs of this project are expected to result in highly efficient OSC with long term device stability. It will also contribute to the training of highly skilled research personnel and to the industrialization of organic photovoltaic technology in Brazil, India and China.