High-performance fab-compatible processed near-infrared organic thin-film photodiode with 3.3×10 12 Jones detectivity and 80% external quantum efficiency

Abstract

A high-performance small molecular near-infrared (NIR) organic photodiode (OPD) including indium (III) phthalocyanine chloride (ClInPc):C60 bulk heterojunction as a photoactive layer is fabricated by using only vacuum processes that are highly compatible with common manufacturing processes used in the photodiode industry. To satisfy simultaneously sufficient absorption of NIR photons, efficient charge extraction, and suppression of undesired dark current injection, the thickness of each constituent layer of NIR-OPD is carefully adjusted. Optical simulations on absorption profiles of NIR photons within a layered OPD structure combined with dark current analyses suggest the optimized device architecture of indium tin oxide/molybdenum oxide/ClInPc:C60 (120 nm)/C60/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline/aluminum. Due to the sufficiently thin active layer thickness, a detectivity (D*) spectrum of the optimized OPD well reflects the absorption feature of ClInPc:C60, with a remarkable detection band at the NIR region with a peak dark-current-based D* of 4.5 × 10 12 Jones and a maximum noise-current-based D* of 3.3 × 10 12 Jones. Furthermore, a low noise equivalent power of 6.13 × 10 −14 W/Hz 0.5 , wide linear dynamic range of 77.2 dB, and fast enough temporal response with a -3dB frequency of 2.85 kHz are demonstrated, that can be ascribed to not only the excellent light absorbing-ability of ClInPc:C60 but also the well-designed diode architecture with effectively suppressed dark current even in a thin active film thickness of 120 nm. © 2019 Elsevier B.V.