Bulk- and layer-heterojunction phototransistors based on poly [2-methoxy-5-(2′-ethylhexyloxy-p-phenylenevinylene)] and PbS quantum dot hybrids

The responsivity (R) of a thin film photodetector is proportional to the product of its photo-induced carrier density (n) and mobility (μ). However, when choosing between layer heterojunction (LH) and bulk heterojunction (BH) field-effect phototransistors (FEpTs), it is still unclear which of the two device structures is more conducive to photodetection. A comparison study is performed on the two structures based on polymer and PbS quantum dot hybrids. Both devices exhibit ambipolar behavior, with μE ≈ μH = 3.7 cm2 V−1 s−1 for BH-FEpTs and μH = 36 cm2 V−1 s−1 and μE = 52 cm2 V−1 s−1 for LH-FEpTs. Because of the improvements in μ and the channel order degree (α), the responsivity of LH-FEpTs is as high as 101 A/W, which is as much as two orders of magnitude higher than that of BH-FEpTs (10−1A/W) under the same conditions. Although the large area of the BH improves both the exciton separation degree (β) and n in the BH-FEpT, the lack of an effective transport mechanism becomes the main constraint on high de...

[1]  G. Konstantatos,et al.  Hybrid graphene-quantum dot phototransistors with ultrahigh gain. , 2011, Nature nanotechnology.

[2]  Dong Hee Shin,et al.  High photoresponsivity in an all-graphene p–n vertical junction photodetector , 2014, Nature Communications.

[3]  Zhenan Bao,et al.  High‐Performance Phototransistors Based on Single‐Crystalline n‐Channel Organic Nanowires and Photogenerated Charge‐Carrier Behaviors , 2013 .

[4]  Uli Lemmer,et al.  Near-infrared imaging with quantum-dot-sensitized organic photodiodes , 2009 .

[5]  F. Wise,et al.  Electronic structure and optical properties of PbS and PbSe quantum dots , 1997 .

[6]  A. Rogach,et al.  Quantum dot field effect transistors , 2013 .

[7]  Haixin Chang,et al.  Graphene and graphene-like two-dimensional materials in photodetection: mechanisms and methodology. , 2014, ACS nano.

[8]  N. Peres,et al.  Field-Effect Tunneling Transistor Based on Vertical Graphene Heterostructures , 2011, Science.

[9]  Feng Yan,et al.  Highly sensitive organic near-infrared phototransistors based on poly(3-hexylthiophene) and PbS quantum dots , 2012 .

[10]  Illan J. Kramer,et al.  The architecture of colloidal quantum dot solar cells: materials to devices. , 2014, Chemical reviews.

[11]  Yiyu Feng,et al.  A layer-nanostructured assembly of PbS quantum dot/multiwalled carbon nanotube for a high-performance photoswitch , 2014, Scientific Reports.

[12]  Liyong Niu,et al.  Photosensitive Graphene Transistors , 2014, Advanced materials.

[13]  G. Konstantatos,et al.  Ultrasensitive solution-cast quantum dot photodetectors , 2006, Nature.

[14]  E. Lifshitz,et al.  PbSe-Based Colloidal Core/Shell Heterostructures for Optoelectronic Applications , 2014, Materials.

[15]  O. Voznyy,et al.  25th Anniversary Article: Colloidal Quantum Dot Materials and Devices: A Quarter‐Century of Advances , 2013, Advanced materials.

[16]  T. Lian,et al.  Multiple exciton generation and dissociation in PbS quantum dot-electron acceptor complexes. , 2012, Nano letters.

[17]  Yunfei Zhou,et al.  Bulk-heterojunction hybrid solar cells based on colloidal nanocrystals and conjugated polymers , 2010 .

[18]  Feng Yan,et al.  Infrared Photodetectors Based on CVD‐Grown Graphene and PbS Quantum Dots with Ultrahigh Responsivity , 2012, Advanced materials.

[19]  G. Konstantatos,et al.  Enhanced infrared photovoltaic efficiency in PbS nanocrystal/semiconducting polymer composites: 600-fold increase in maximum power output via control of the ligand barrier , 2005 .

[20]  Marco R. Cavallari,et al.  Determination of carrier mobility in MEH-PPV thin-films by stationary and transient current techniques , 2012 .

[21]  Y. Long,et al.  Phenanthrene Condensed Thiadiazoloquinoxaline Donor-Acceptor Polymer for Phototransistor Applications , 2015 .

[22]  M. Loi,et al.  High Performance Ambipolar Field‐Effect Transistor of Random Network Carbon Nanotubes , 2012, Advanced materials.

[23]  W. Su,et al.  Nanoparticle-tuned self-organization of a bulk heterojunction hybrid solar cell with enhanced performance. , 2012, ACS nano.

[24]  K. Novoselov,et al.  Strong Light-Matter Interactions in Heterostructures of Atomically Thin Films , 2013, Science.

[25]  G. Konstantatos,et al.  Solution-processed PbS quantum dot infrared photodetectors and photovoltaics , 2005, Nature materials.

[26]  D. Chung,et al.  Low voltage, hysteresis free, and high mobility transistors from all-inorganic colloidal nanocrystals. , 2012, Nano letters.

[27]  Delia J. Milliron,et al.  Chemistry of Doped Colloidal Nanocrystals , 2013 .

[28]  T. Lian,et al.  Multiple exciton dissociation and hot electron extraction by ultrafast interfacial electron transfer from PbS QDs , 2014 .

[29]  W. Fann,et al.  Review of Morphology Dependent Charge Carrier Mobility in MEH-PPV , 2010 .