@article{LuBlakesleyHimmelbergeretal.2013,
  author    = {Lu, Guanghao and Blakesley, James C. and Himmelberger, Scott and Pingel, Patrick and Frisch, Johannes and Lieberwirth, Ingo and Salzmann, Ingo and Oehzelt, Martin and Di Pietro, Riccardo and Salleo, Alberto and Koch, Norbert and Neher, Dieter},
  title     = {Moderate doping leads to high performance of semiconductor/insulator polymer blend transistors},
  series = {Nature Communications},
  volume    = {4},
  journal   = {Nature Communications},
  number    = {1-2},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/ncomms2587},
  pages     = {8},
  year      = {2013},
  abstract  = {Polymer transistors are being intensively developed for next-generation flexible electronics. Blends comprising a small amount of semiconducting polymer mixed into an insulating polymer matrix have simultaneously shown superior performance and environmental stability in organic field-effect transistors compared with the neat semiconductor. Here we show that such blends actually perform very poorly in the undoped state, and that mobility and on/off ratio are improved dramatically upon moderate doping. Structural investigations show that these blend layers feature nanometre-scale semiconductor domains and a vertical composition gradient. This particular morphology enables a quasi three-dimensional spatial distribution of semiconductor pathways within the insulating matrix, in which charge accumulation and depletion via a gate bias is substantially different from neat semiconductor, and where high on-current and low off-current are simultaneously realized in the stable doped state. Adding only 5 wt\% of a semiconducting polymer to a polystyrene matrix, we realized an environmentally stable inverter with gain up to 60.},
  language  = {en}
}
@article{LuDiPietroKoellnetal.2016,
  author    = {Lu, Guanghao and Di Pietro, Riccardo and K{\"o}lln, Lisa Sophie and Nasrallah, Iyad and Zhou, Ling and Mollinger, Sonya and Himmelberger, Scott and Koch, Norbert and Salleo, Alberto and Neher, Dieter},
  title     = {Dual-Characteristic Transistors Based on Semiconducting Polymer Blends},
  series = {Advanced electronic materials},
  volume    = {2},
  journal   = {Advanced electronic materials},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {2199-160X},
  doi       = {10.1002/aelm.201600267},
  pages     = {2344 -- 2351},
  year      = {2016},
  abstract  = {A dual-characteristic polymer field-effect transistor has markedly different characteristics in low and high voltage operations. In the low-voltage range (<5 V) it shows sharp subthreshold slopes (0.3-0.4 V dec\&\#8722;1), using which a low-voltage inverter with gain 8 is realized, while high-voltage (>5 V) induces symmetric current with regard to drain and gate voltages, leading to discrete differential (trans) conductances.},
  language  = {en}
}
@article{LuKochNeher2015,
  author    = {Lu, Guanghao and Koch, Norbert and Neher, Dieter},
  title     = {In-situ tuning threshold voltage of field-effect transistors based on blends of poly(3-hexylthiophene) with an insulator electret},
  series = {Applied physics letters},
  volume    = {107},
  journal   = {Applied physics letters},
  number    = {6},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0003-6951},
  doi       = {10.1063/1.4928554},
  pages     = {5},
  year      = {2015},
  abstract  = {Blending the conjugated polymer poly(3-hexylthiophene) (P3HT) with the insulating electret polystyrene (PS), we show that the threshold voltage V-t of organic field-effect transistors (OFETs) can be easily and reversely tuned by applying a gate bias stress at 130 degrees C. It is proposed that this phenomenon is caused by thermally activated charge injection from P3HT into PS matrix, and that this charge is immobilized within the PS matrix after cooling down to room temperature. Therefore, room-temperature hysteresis-free FETs with desired V-t can be easily achieved. The approach is applied to reversely tune the OFET mode of operation from accumulation to depletion, and to build inverters. (C) 2015 AIP Publishing LLC.},
  language  = {en}
}