Organic solar cells with stacked bulk heterojutaction（BHJ） are investigated based on conjugated polymer. By using the solution spin-coating method, Poly[2-methoxy, 5-（2＇ -ethyl-hexyloxy） -1,4-phenylene vinylene] ...Organic solar cells with stacked bulk heterojutaction（BHJ） are investigated based on conjugated polymer. By using the solution spin-coating method, Poly[2-methoxy, 5-（2＇ -ethyl-hexyloxy） -1,4-phenylene vinylene] （MEH-PPV） and ZnO nanoparticles （50 nm） are mixed as the optical sense layer. Ag is used as inter-layer to connect the upper BHJ cell and the lower cell. The structures are ITO/PEDOT：PSS/MEH-PPV lAg / MEH-PPV：ZnO/Al. The open circuit voltage （Voc） of a stacked cell is about 3.7 times of that of an individual organic solar cell （ITO/PEDOT：PSS/MEH-PPV/Al）. The short circuit current （Jsc） of a stacked cell is increased by about 1.6 times of that of individual one.展开更多
Series devices of ITO/ZnO/ZnO nanorods/MEH-PPV/Al have been fabricated.ITO and ZnO nanorods of some devices are treated by O_(2) plasma.The electroluminescence of different devices is detected under different biases.U...Series devices of ITO/ZnO/ZnO nanorods/MEH-PPV/Al have been fabricated.ITO and ZnO nanorods of some devices are treated by O_(2) plasma.The electroluminescence of different devices is detected under different biases.UV electroluminescence of ZnO nanorods at 380 nm is observed in all the devices.The intensity of 380 nm increases when both ITO and ZnO nanorods are treated.The turn-on voltage of the treated device is lower than that of the non-treated device,and the EL power is enhanced.When the thickness of MEH-PPV is sufficiently thin,only 380 nm electroluminescence,besides a weak defect emission at 760 nm,is detected.The enhancement mechanism of the electroluminescence of the treated devices is discussed.展开更多
An electrical characteristic model of organic thin film transistors(OTFTs)is presented.The model is based on the capacitance modulation principle,i.e.the accumulated charges in the conductive channel are induced by th...An electrical characteristic model of organic thin film transistors(OTFTs)is presented.The model is based on the capacitance modulation principle,i.e.the accumulated charges in the conductive channel are induced by the gate capacitance under an electric field.The current-voltage characteristics of the presented model are compared with the experimental data.According to the electrical characteristics of the model,it is explained that the operating process of OTFTs is actually modulated by the capacitance.The gate capacitance,the contact resistance,the contact barrier,and the field-effect mobility have a significant effect on the performance of OTFTs.展开更多
We prepare a tandem (OLED) with two independent units and three electrodes. One of the units consists of ITO/TPD/Al_(q3):DCJTB (5%)/LiF/Al/Au, and the other is Al/Au/TPD/Al_(q3)/LiF/Al. Two units sharing one transpare...We prepare a tandem (OLED) with two independent units and three electrodes. One of the units consists of ITO/TPD/Al_(q3):DCJTB (5%)/LiF/Al/Au, and the other is Al/Au/TPD/Al_(q3)/LiF/Al. Two units sharing one transparent intermediate electrode Al/Au, together constitute the entire device. With the same current density, the voltage of the entire device is approximately equal to the sum of two units. The current efficiency of the entire device is several times higher than the sum up of two components. Without directly contacting an external power supply, the bi-metal intermediate electrode has the ability to produce electrons and holes for two adjacent emitting units, respectively. This kind of tandem device is characterized by controllable emission color and higher current efficiency than its two components added up.展开更多
In order to take advantage of organic and inorganic materials,we chose the polymer MEH-PPV as the luminous layer and ZnS as the electron transporting layer to prepare hybrid organic-inorganic light-emitting diodes(HOI...In order to take advantage of organic and inorganic materials,we chose the polymer MEH-PPV as the luminous layer and ZnS as the electron transporting layer to prepare hybrid organic-inorganic light-emitting diodes(HOILEDs):ITO/MEH-PPV(~70 nm)/ZnS(20 nm)/Al by thermal evaporation and spin coating.Compared with the single-layer device ITO/MEH-PPV(~70 nm)/Al,spectral broadening and a slightly red shift are observed.Compared with the pure organic device ITO/MEH-PPV(~70 nm)/BCP(20 nm)/Al and combined with the energy level structure diagram,it is concluded that the spectral broadening and red shift are due to the exciplex luminescence at the interface between MEH-PPV and ZnS or BCP.In addition,the hybrid inorganic-organic device shows a lower turn-on voltage,but the current efficiency is lower than that of the pure organic device with the same structure.展开更多
The upconversion luminescence of oxyfluoride transparent vitroceramics codoped with Er^(3+) and Yb^(3+) has been studied experimentally. There are microcrystallites to form in the oxyfluoride glass which is treated ov...The upconversion luminescence of oxyfluoride transparent vitroceramics codoped with Er^(3+) and Yb^(3+) has been studied experimentally. There are microcrystallites to form in the oxyfluoride glass which is treated over its transi tion temperature, and the transparent vitroceramics are obtained. The vitroceramics has the better transparency and a high upconversion luminescent efficiency. Our results show that there is strong energy transfer between Er^(3+) and Yb^(3+) in the vitroceramics, which results in the change of the upconversion spectra with intensity of excitation laser.展开更多
基金the National Natural Science Foundation of China ( 60576016 and 10774013)National "863" Program (2006AA03Z0412)"973" Program(2003CB314707)
文摘Organic solar cells with stacked bulk heterojutaction（BHJ） are investigated based on conjugated polymer. By using the solution spin-coating method, Poly[2-methoxy, 5-（2＇ -ethyl-hexyloxy） -1,4-phenylene vinylene] （MEH-PPV） and ZnO nanoparticles （50 nm） are mixed as the optical sense layer. Ag is used as inter-layer to connect the upper BHJ cell and the lower cell. The structures are ITO/PEDOT：PSS/MEH-PPV lAg / MEH-PPV：ZnO/Al. The open circuit voltage （Voc） of a stacked cell is about 3.7 times of that of an individual organic solar cell （ITO/PEDOT：PSS/MEH-PPV/Al）. The short circuit current （Jsc） of a stacked cell is increased by about 1.6 times of that of individual one.
基金Supported by the National Basic Research Program of China(2010CB327705)the National Natural Science Foundation of China(10974013 and 51272022)+1 种基金the New Century Excellent Talents in University(NCET-10-0220)the Fundamental Research Funds for the Central Universities(2012JBZ001).
文摘Series devices of ITO/ZnO/ZnO nanorods/MEH-PPV/Al have been fabricated.ITO and ZnO nanorods of some devices are treated by O_(2) plasma.The electroluminescence of different devices is detected under different biases.UV electroluminescence of ZnO nanorods at 380 nm is observed in all the devices.The intensity of 380 nm increases when both ITO and ZnO nanorods are treated.The turn-on voltage of the treated device is lower than that of the non-treated device,and the EL power is enhanced.When the thickness of MEH-PPV is sufficiently thin,only 380 nm electroluminescence,besides a weak defect emission at 760 nm,is detected.The enhancement mechanism of the electroluminescence of the treated devices is discussed.
基金Supported by the National Natural Science Foundation of China under Grant No 51272022the National Basic Research Program of China under Grant No 2010CB327704+2 种基金New Century Excellent Thlents in University under Grant No NCET-10-0220the Research Fund for the Doctoral Program of Higher Education under Grant No 20120009130005the Fundamental Research Funds for the Central Universities under Grant No 2012JBZ001.
文摘An electrical characteristic model of organic thin film transistors(OTFTs)is presented.The model is based on the capacitance modulation principle,i.e.the accumulated charges in the conductive channel are induced by the gate capacitance under an electric field.The current-voltage characteristics of the presented model are compared with the experimental data.According to the electrical characteristics of the model,it is explained that the operating process of OTFTs is actually modulated by the capacitance.The gate capacitance,the contact resistance,the contact barrier,and the field-effect mobility have a significant effect on the performance of OTFTs.
基金the National Natural Science Foundation of China under Grant Nos 10974013 and 60978060the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20090009110027+6 种基金Beijing Municipal Natural Science Foundation under Grant No 1102028the National Natural Science Foundation of China for Distinguished Young Scholar under Grant No 60825407Beijing Municipal Science and Technology Commission under Grant No Z090803044009001the National Basic Research Program of China under Grant No 2010CB327704the New Century Excellent Talents in University under Grant No NCET-10-0220the Fundamental Research Funds for the Central Universities under Grant No 2012JBZ001the Science and Technology Innovation Fund for Outstanding PhD Students of Beijing Jiaotong University under Grant No 48034。
文摘We prepare a tandem (OLED) with two independent units and three electrodes. One of the units consists of ITO/TPD/Al_(q3):DCJTB (5%)/LiF/Al/Au, and the other is Al/Au/TPD/Al_(q3)/LiF/Al. Two units sharing one transparent intermediate electrode Al/Au, together constitute the entire device. With the same current density, the voltage of the entire device is approximately equal to the sum of two units. The current efficiency of the entire device is several times higher than the sum up of two components. Without directly contacting an external power supply, the bi-metal intermediate electrode has the ability to produce electrons and holes for two adjacent emitting units, respectively. This kind of tandem device is characterized by controllable emission color and higher current efficiency than its two components added up.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10974013 and 60978060the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20090009110027+6 种基金Beijing Municipal Natural Science Foundation under Grant No 1102028the National Natural Science Foundation of China for Distinguished Young Scholar(No 60825407)Beijing Municipal Science and Technology Commission under Grant No Z090803044009001the National Basic Research Program of China under Grant No 2010CB327704the New Century Excellent Talents in University under Grant No NCET-10-0220the Fundamental Research Funds for the Central Universities under Grant No 2012JBZ001the Science and Technology Innovation Fund for Outstanding PhD Students of Beijing Jiaotong University(No 48034).
文摘In order to take advantage of organic and inorganic materials,we chose the polymer MEH-PPV as the luminous layer and ZnS as the electron transporting layer to prepare hybrid organic-inorganic light-emitting diodes(HOILEDs):ITO/MEH-PPV(~70 nm)/ZnS(20 nm)/Al by thermal evaporation and spin coating.Compared with the single-layer device ITO/MEH-PPV(~70 nm)/Al,spectral broadening and a slightly red shift are observed.Compared with the pure organic device ITO/MEH-PPV(~70 nm)/BCP(20 nm)/Al and combined with the energy level structure diagram,it is concluded that the spectral broadening and red shift are due to the exciplex luminescence at the interface between MEH-PPV and ZnS or BCP.In addition,the hybrid inorganic-organic device shows a lower turn-on voltage,but the current efficiency is lower than that of the pure organic device with the same structure.
基金Supported in Part by National Laboratory of Infrared Physics,Shanghai Institute of Technical Physics,Chinese Academy of Sciences,and Paper's Foudation of Northern Jiaotong university.
文摘The upconversion luminescence of oxyfluoride transparent vitroceramics codoped with Er^(3+) and Yb^(3+) has been studied experimentally. There are microcrystallites to form in the oxyfluoride glass which is treated over its transi tion temperature, and the transparent vitroceramics are obtained. The vitroceramics has the better transparency and a high upconversion luminescent efficiency. Our results show that there is strong energy transfer between Er^(3+) and Yb^(3+) in the vitroceramics, which results in the change of the upconversion spectra with intensity of excitation laser.
