title: Squaraine based solution processed inverted bulk heterojunction solar cells processed in air.
abstract: Inverted bulk heterojunction solar cells based on low temperature solution processed squaraine (SQ) and [6,6]-phenyl C71 butyric acid methyl-ester (PC71BM) with varying blend ratios were made in air. An optimized bulk heterojunction device of SQ and PC71BM (with a blend ratio of 1 : 6) showed a power conversion efficiency (PCE) of 2.45% with an incident photon to current conversion efficiency of 65% at 680 nm and a spectral window extending to the NIR region. The devices also showed an enhanced PCE value of 4.12% upon continuous illumination from an AM1.5G light source of intensity 1 Sun. The intensity dependent photocurrent studies showed a monomolecular recombination mechanism in the photovoltaic device performance. The device stored in air showed reasonable stability for a period of one month.
authors.affiliation: School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, CET Campus, Engineering College P O, Thiruvananthapuram, Kerala PIN 695016, India. manoj@iisertvm.ac.in.
authors.forename: P C Reshmi
authors.initials: PC
authors.lastname: Varma
authors.affiliation: School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, CET Campus, Engineering College P O, Thiruvananthapuram, Kerala PIN 695016, India. manoj@iisertvm.ac.in.
authors.forename: Manoj A G
authors.initials: MA
authors.lastname: Namboothiry