Inkjet-Printed Tin Oxide Hole-Blocking Layers for\nOrganic Photodiodes

Abstract

We investigated the fabrication of\ninkjet-printed SnO₂ hole-blocking layers (HBLs) for organic\nphotodiodes (OPDs). HBLs\nprinted at different drop spacings were fabricated, and the effect\nof printing parameters on the layer quality was analyzed. These layers\nwere incorporated into polymer:nonfullerene bulk-heterojunction OPDs,\nand their influence on the rectification, spectral responsivity, specific\ndetectivity, and detection speed of the device was investigated. The\nOPDs fabricated with a drop spacing of 35 μm corresponding to\na thickness of 31 ± 7 nm exhibited the best overall performance.\nThese OPDs reached state-of-the-art performance with spectral responsivities\nof >0.5 A W^–1, low dark current densities in\nthe\norder of 5 nA cm^–2, bandwidths of >2 MHz, and\npeak\nspecific detectivities of ∼10¹¹ Jones at 740 nm.