The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2...The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2＇-ethylhexyloxy）-p-phenylene vinylene） （MEH-PPV） hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density mad electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Fu^hermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect cur- rent-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.展开更多
Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and...Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and IIG） into a polymer main chain to form A-A＇ polymer PIIG-BTz could lower highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm2 V 1 s-i was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor （A-A＇） structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors.展开更多
基金supported by the National Basic Research Program of China (Grant No.2007CB310407)Foundation for Innovative Research Groups of the NSFC (Grant No.61021061)+1 种基金the National Natural Science Foundation of China (Grant Nos.50972023 and 61071028)the International S&T Cooperation Program of China (Grant No.2006DFA53410)
文摘The conventional charge transport models based on density- and field-dependent mobility, only having a non-Arrhenius tem- perature dependence, cannot give good current-voltage characteristics of poly （2-methoxy-5-（2＇-ethylhexyloxy）-p-phenylene vinylene） （MEH-PPV） hole-only devices. In this paper, we demonstrate that the current-voltage characteristics can give a good unified description of the temperature, carrier density mad electric field dependence of mobility based on both the Arrhenius temperature dependence and the non-Arrhenius temperature dependence. Fu^hermore, we perform a systematic study of charge transport and electrical properties for MEH-PPV. It is shown that the boundary carrier density has an important effect on the current-voltage characteristics. Too large or too small values of boundary carrier density will lead to incorrect cur- rent-voltage characteristics. The numerically calculated carrier density is a decreasing function of the distance to the interface, and the numerically calculated electric field is an increasing function of the distance. Both the maximum of carrier density and the minimum of electric field appear near the interface.
基金supported by the National Natural Science Foundation of China (51173055, 21504026, 51572094)the National Basic Research Program of China (2013CBA01600)the China Postdoctoral Science Foundation (2013M542009)
文摘Balanced carrier transport is observed in acceptor-acceptor （A-A＇） type polymer for ambipolar organic thin-film transistors （OTFTs）. It is found that the incorporation of two electron-accepting moieties （BTz and IIG） into a polymer main chain to form A-A＇ polymer PIIG-BTz could lower highest occupied molecular orbital （HOMO） and lowest unoccupied molecular orbital （LUMO） levels and facilitate good molecular stacking of the polymer. Ambipolar transistor behaviour for PIIG-BTz, with the balanced hole and electron mobilities of 0.030 and 0.022 cm2 V 1 s-i was observed in OTFT devices, respectively. The study in this work reveals that the utilization of acceptor-acceptor （A-A＇） structure in polymer main chain can be a feasible strategy to develop ambipolar polymer semiconductors.
