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Title: Ultrasensitive organic phototransistors with multispectral response based on thin-film/single-crystal bilayer structures

We report on highly efficient organic phototransistors (OPTs) based on thin-film/single-crystal planar bilayer junctions between 5,6,11,12-tetraphenyltetracene (rubrene) and [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PC{sub 61}BM). The OPTs show good field-effect characteristics in the dark, with high hole-mobility (4–5 cm{sup 2} V{sup −1} s{sup −1}), low-contact resistance (20 kΩ cm), and low-operating voltage (≤5 V). Excellent sensing capabilities allow for light detection in the 400–750 nm range, with photocurrent/dark current ratio as high as 4 × 10{sup 4}, responsivity on the order of 20 AW{sup −1} at 27 μW cm{sup −2}, and an external quantum efficiency of 52 000%. Photocurrent generation is attributed to enhanced electron and hole transfer at the interface between rubrene and PC{sub 61}BM, and fast response times are observed as a consequence of the high-mobility of the interfaces. The optoelectronic properties exhibited in these OPTs outperform those typically provided by a-Si based devices, enabling future applications where multifunctionality in a single-device is sought.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [1] ;  [2]
  1. INESC MN and IN, Rua Alves Redol 9, 1000-029 Lisboa (Portugal)
  2. (Portugal)
  3. (United Kingdom)
Publication Date:
OSTI Identifier:
22486168
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 107; Journal Issue: 22; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BUTYRIC ACID; CONNECTORS; DETECTION; ELECTRIC CONTACTS; HOLE MOBILITY; HOLES; LAYERS; MONOCRYSTALS; PHOTOTRANSISTORS; QUANTUM EFFICIENCY; THIN FILMS