We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band ...We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band tail states reproduces well the characteristics of polycrystalline ZnO thin film transistors. Furthermore, using the developed model, we study the effects of defect parameters on the electrical performances of the polycrystalline ZnO thin film transistors.展开更多
The dependence of transistor characteristics on grain boundary （GB） position in short-channel ZnO thin film transistors （TFTs） has been investigated using two-dimensional numerical simulations. To simulate the dev...The dependence of transistor characteristics on grain boundary （GB） position in short-channel ZnO thin film transistors （TFTs） has been investigated using two-dimensional numerical simulations. To simulate the device accurately, both tail states and deep-level states are taken into consideration. It is shown that both the transfer and output characteristics of ZnO TFTs change dramatically with varying GB position, which is different from polycrystalline Si （poly-Si） TFTs. By analysing the mechanism of the carrier transportation in the device, it is revealed that the dependence is derived from the degrees of carrier concentration descent and mobility variation with CB position.展开更多
The grain boundaries （GBs） have a strong effect on the electric properties of ZnO thin film transistors （TFTs）. A novel grain boundary model was developed to analyse the effect. The model was characterized with di...The grain boundaries （GBs） have a strong effect on the electric properties of ZnO thin film transistors （TFTs）. A novel grain boundary model was developed to analyse the effect. The model was characterized with different angles between the orientation of the grain boundary and the channel direction. The potential barriers formed by the grain boundaries increase with the increase of the grain boundary angle, so the degradation of the transistor characteristics increases. When a grain boundary is close to the drain edge, the potential barrier height reduces, so the electric properties were improved.展开更多
Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite qua...Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite quantum dots(PeQDs)as active layer.Typical ZnO thin film transistors did not show a photocurrent under visible light illumination.However,ZnO TFTs decorated with PeQDs exhibited enhanced photocurrent upon exposure to visible light.The device had a responsivity of 567 A/W(617 A/W),a high detectivity of 6.59×10^(13)Jones(1.85×10^(14)J)and a high sensitivity of 10^(7)(10^(8))under green(blue)light at a low drain voltage of 0.1 V.The high photo-responsivity and detectivity under green light resulted from the combination of short ligands in the QDs films and the high mobility of the spray coated ZnO films.Those results are relevant for the development of low cost and low energy consumption phototransistors working in the visible range.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.K50510250001)
文摘We report a model of the carrier transport and the subgap density of states in a polycrystalline ZnO film for simulating a polycrystalline ZnO thin film transistor. This simple model considering the deep and the band tail states reproduces well the characteristics of polycrystalline ZnO thin film transistors. Furthermore, using the developed model, we study the effects of defect parameters on the electrical performances of the polycrystalline ZnO thin film transistors.
基金Project supported by the National Natural Science Foundation of China (Grant No. 50872112)NPU Foundation for Fundamental Research,China (Grant No. JC201017)
文摘The dependence of transistor characteristics on grain boundary （GB） position in short-channel ZnO thin film transistors （TFTs） has been investigated using two-dimensional numerical simulations. To simulate the device accurately, both tail states and deep-level states are taken into consideration. It is shown that both the transfer and output characteristics of ZnO TFTs change dramatically with varying GB position, which is different from polycrystalline Si （poly-Si） TFTs. By analysing the mechanism of the carrier transportation in the device, it is revealed that the dependence is derived from the degrees of carrier concentration descent and mobility variation with CB position.
基金supported by the National Natural Science Foundation of China (Grant Nos 50677014,50602014 and 10874042)the National High Technology Joint Research Program of China (Grant No 2006AA04A104)the Science-Technology Foundation of Hunan Province of China (Grant Nos 2008RS4003 and 07jj107)
文摘The grain boundaries （GBs） have a strong effect on the electric properties of ZnO thin film transistors （TFTs）. A novel grain boundary model was developed to analyse the effect. The model was characterized with different angles between the orientation of the grain boundary and the channel direction. The potential barriers formed by the grain boundaries increase with the increase of the grain boundary angle, so the degradation of the transistor characteristics increases. When a grain boundary is close to the drain edge, the potential barrier height reduces, so the electric properties were improved.
基金This work was supported by the Technology Innovation Program(No.20011317)Development of an adhesive material capable of morphing more than 50%for flexible devices with a radius of curvature of 1 mm or less funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite quantum dots(PeQDs)as active layer.Typical ZnO thin film transistors did not show a photocurrent under visible light illumination.However,ZnO TFTs decorated with PeQDs exhibited enhanced photocurrent upon exposure to visible light.The device had a responsivity of 567 A/W(617 A/W),a high detectivity of 6.59×10^(13)Jones(1.85×10^(14)J)and a high sensitivity of 10^(7)(10^(8))under green(blue)light at a low drain voltage of 0.1 V.The high photo-responsivity and detectivity under green light resulted from the combination of short ligands in the QDs films and the high mobility of the spray coated ZnO films.Those results are relevant for the development of low cost and low energy consumption phototransistors working in the visible range.
