Polymer infrared photo-detector with high sensitivity up to 1100 nm

a b s t r a c t We reported a low band-gap conjugated polymer, poly(2,3-bis(4-(2-ethylhexyloxy)phenyl)-5,7- di(thiophen-2-yl)thieno(3,4-b)pyrazine) (PDTTP), was studied for the near infrared (NIR) photo-detector application. PDTTP shows intense absorption in NIR wavelength (to 1000 nm) and the estimated optical and electrochemical band-gaps of PDTTP are quite small around 1.15 eV and 1.08 eV, respectively. The low band-gap and the extended long wavelength absorption originates from the introduction of alter- nating TP units when its parent polythieno(3,4-b)pyrazine shows excellent narrow band-gap properties. Therefore, the relatively low band-gap and intense absorption in long wavelength of PDTTP make itself a promising candidate for near-infrared photo-detector. The hole mobility of the PDTTP measured from the bottom contact field effect transistor is around 1.40 × 10 −3 cm 2 /V s with a on/off ratio of 2100. The photo-detector based on bulk hetero-junction PDTTP and (6,6)-phenyl-C61-butyric acid methyl ester blend (PCBM) has the incident photon-to-electron conversion efficiency 28.9% at 1000 nm (−5 V) and 6.2% at 1100 nm (−5 V). This photo-detector can be operated at a high-speed of 1 MHz. The experimen- tal result suggests the potential applications of low band-gap conjugated polymers on near-infrared photo-detectors.

[1]  O. Inganäs,et al.  A New Donor–Acceptor–Donor Polyfluorene Copolymer with Balanced Electron and Hole Mobility† , 2007 .

[2]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[3]  Yongfang Li,et al.  Synthesis and electroluminescence of novel copolymers containing crown ether spacers , 2003 .

[4]  Mm Martijn Wienk,et al.  Low-band gap poly(di-2-thienylthienopyrazine):fullerene solar cells , 2006 .

[5]  W. Walker,et al.  Visible and Near-Infrared Absorbing, Low Band Gap Conjugated Oligomers Based on Cyclopentadieneones , 2008 .

[6]  Xiong Gong,et al.  Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology , 2005 .

[7]  F. Krebs,et al.  Low band gap poly-thienopyrazines for solar cells—Introducing the 11-thia-9,13-diaza-cyclopenta[b]triphenylenes , 2007 .

[8]  C. Brabec,et al.  Origin of the Open Circuit Voltage of Plastic Solar Cells , 2001 .

[9]  Bumjoon J. Kim,et al.  The influence of poly(3-hexylthiophene) regioregularity on fullerene-composite solar cell performance. , 2008, Journal of the American Chemical Society.

[10]  S. Jenekhe,et al.  New Didecyloxyphenylene−Acceptor Alternating Conjugated Copolymers: Synthesis, Properties, and Optoelectronic Device Applications , 2008 .

[11]  Yang Yang,et al.  Synthesis, characterization, and photovoltaic properties of a low band gap polymer based on silole-containing polythiophenes and 2,1,3-benzothiadiazole. , 2008, Journal of the American Chemical Society.

[12]  O. Inganäs,et al.  Polymer solar cells with low-bandgap polymers blended with C70-derivative give photocurrent at 1 μm , 2006 .

[13]  Xianyu Deng,et al.  Photocurrent response wavelength up to 1.1μm from photovoltaic cells based on narrow-band-gap conjugated polymer and fullerene derivative , 2006 .

[14]  O. Inganäs,et al.  New low band gap alternating polyfluorene copolymer-based photovoltaic cells , 2007 .

[15]  O. Inganäs,et al.  Enhanced Photocurrent Spectral Response in Low‐Bandgap Polyfluorene and C70‐Derivative‐Based Solar Cells , 2005 .

[16]  Mats Andersson,et al.  An alternating low band-gap polyfluorene for optoelectronic devices , 2006 .

[17]  Benjamin C. Duck,et al.  Poly(2,3-dihexylthieno[3,4-b]pyrazine) via GRIM Polymerization: Simple Preparation of a Solution Processable, Low-Band-Gap Conjugated Polymer , 2008 .

[18]  S. Forrest,et al.  Organic solar cells with sensitivity extending into the near infrared , 2005 .

[19]  D. Bradley,et al.  Polymer Transfer Printing: Application to Layer Coating, Pattern Definition, and Diode Dark Current Blocking , 2008 .

[20]  Andrew G. Glen,et al.  APPL , 2001 .

[21]  O. Inganäs,et al.  A Conjugated Polymer for Near Infrared Optoelectronic Applications , 2007 .

[22]  Jow-Tsong Shy,et al.  Infrared photocurrent response of charge-transfer exciton in polymer bulk heterojunction , 2008 .

[23]  O. Inganäs,et al.  Correlation between oxidation potential and open-circuit voltage of composite solar cells based on blends of polythiophenes/ fullerene derivative , 2004 .

[24]  Barry P Rand,et al.  Thin-film organic position sensitive detectors , 2003, IEEE Photonics Technology Letters.

[25]  Michael D. McGehee,et al.  Polymer-based solar cells , 2007 .

[26]  J. Moon,et al.  High-Detectivity Polymer Photodetectors with Spectral Response from 300 nm to 1450 nm , 2009, Science.

[27]  O. Inganäs,et al.  Design, Synthesis and Properties of Low Band Gap Polyfluorenes for Photovoltaic Devices , 2005 .

[28]  Luping Yu,et al.  Plastic Near‐Infrared Photodetectors Utilizing Low Band Gap Polymer , 2007 .

[29]  Poly(5,6-dithiooctylisothianaphtene), a new low band gap polymer: spectroscopy and solar cell construction , 2003 .

[30]  Wen‐Chang Chen,et al.  Small band gap conjugated polymers based on thiophene–thienopyrazine copolymers , 2007 .

[31]  Polymer infrared proximity sensor , 2008 .

[32]  S. Rasmussen,et al.  A second look at polythieno[3,4-b]pyrazines: Chemical vs electrochemical polymerization and its effect on band gap , 2003 .

[33]  David L. Carroll,et al.  High-efficiency photovoltaic devices based on annealed poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1- phenyl-(6,6)C61 blends , 2005 .

[34]  O. Inganäs,et al.  High photovoltage achieved in low band gap polymer solar cells by adjusting energy levels of a polymer with the LUMOs of fullerene derivatives , 2008 .

[35]  Gang Li,et al.  “Solvent Annealing” Effect in Polymer Solar Cells Based on Poly(3‐hexylthiophene) and Methanofullerenes , 2007 .

[36]  Yang Yang,et al.  High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends , 2005 .