S1 Supporting information Open Atmosphere Processed Stable Perovskite Solar Cells Using Molecular Engineered, Dopant-Free, Highly Hydrophobic Polymeric Hole Transporting Materials: Influence of Thiophene and Alkyl Chain on Power Conversion Efficiency Prem Jyoti Singh Rana, † [a] Rajendra Kumar Gunasekaran, † [a] Sung Heum Park, [b] Vellaiappillai Tamilavan, [b] Senthil Karuppanan, [c] Hee-Je Kim, [a] Kandasamy Prabakar [a] a Department of Electrical Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan-46241, Republic of Korea. b Department of Physics, Pukyong National University, Busan 608-737, Republic of Korea. c Department of Physics, Bannari Amman Institute of Technology, Sathyamangalam 638 401, Tamil Nadu, India. †These authors contribute equally to this work. Corresponding Author: prabakar@pusan.ac.kr