Prashant Sonar*,a Hong Duc Pham,a Zhifang Wu,b Sagar Jain,c Hongwei Hu,d Yabing Qi,b Yeng Ming Lam d

 

a. Institute of Future Environment and School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD-4001, Australia.
b Energy Materials and Surface Sciences Unit (EMSS),Okinawa Institute of Science and Technology Graduate University (OIST) 1919-1 Tancha, Onna-son, Kunigami-gun
Okinawa, Japan 904-0495
c
Department of Chemistry and Centre for Plastic Electronics, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
d School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore.

 

The research on perovskite solar cells (PSCs) has gained a huge attention in scientific and industrial community mainly due to their ability to reach the performance close to that of the existing high performance silicon and other inorganic material based solar cell technologies. The world record power conversion efficiency (PCE) of PSCs has now exceeded 22%. The hole transport materials (HTM) is one of the most important and critical component of a PSC which prevents the active perovskite layer with the metal electrode, and blocks moisture and oxygen penetration, which leads to high stability. In addition to that HTM acts as a charge transporting as well as a charge selective layer, which also suppresses charge recombination and enhances higher PCE.

Among these various functional HTMs, in the small organic molecule category, 2,2’,7,7’-tetrakis(N,N’-di-pmethoxyphenylamino)-9,9’-spirbiuorene (SPIRO-OMeTAD) has been proven to be the best choice of materials as its use resulted in a world record 20.8% efficiency in PSCs.1 Among other classes of organic materials, polymer materials approached the highest performance, 18.4% (with dopants). However, a very high cost of SPIRO-OMeTAD HTM and multistep synthesis of polydisperse polymers restricts the development of low cost and large area flexible perovskite solar cells. Herein, we have designed and synthesized two novel, simple and low cost HTMs based on linear π-conjugated linkers and TPA end-cappers which gives almost 17% PCE using both standard mesoporous and inverted geometry with high stability. 3-5

References

[1]. D. Bi, W. Tress, M. I. Dar, P. Gao, J. Luo, C. Renevier, K. Schenk, A. Abate, F. Giordano, J.-P. C. Baena, J.-D. Decoppet, S. M. Zakeeruddin, M. K. Nazeeruddin, M. Grätzel, A. Hagfeldt, Sci. Adv. 2016, 2, e1501170; [2] N. J. Jeon, J. H. Noh, W. S. Yang, Y. C. Kim, S. Ryu, J. Seo, S. I. Seok, Nature 2015, 517, 476; [3] H. D. Pham, Z. Wu, L. K. Ono, S. Manzhos, K. Feron, N. Motta, Y. Qi, P. Sonar, Adv. Electron. Mater. 2017, accepted; [4] H. D. Pham, H. Hu, K. Feron, S. Manzhos, H. Wang, Y. M. Lam, P. Sonar, Solar RRL. 2017, accepted;[5] Patent filed.