Inter-dune lake sediment cores are ideal and unavailable materials for study climate and environmental changes of arid region.The precious dating of lake sediment cores is required for carrying out high resolution cli...Inter-dune lake sediment cores are ideal and unavailable materials for study climate and environmental changes of arid region.The precious dating of lake sediment cores is required for carrying out high resolution climate and environmental changes with these cores.The Badain Jaran inter-dune lake group embedding in the sand sea is the展开更多
Hydrogen bonding configurations and hydrogen content in hydrogenated amorphous silicon (a-Si:H) thin films prepared at different precursor gas temperatures with undiluted silane have been investigated by means of Four...Hydrogen bonding configurations and hydrogen content in hydrogenated amorphous silicon (a-Si:H) thin films prepared at different precursor gas temperatures with undiluted silane have been investigated by means of Fourier transform infrared (FTIR) spectroscopy.The results show that the gas temperature before precursor gases entering the glow-discharge zone re-markably influences the hydrogen bonding configurations and the hydrogen content in a-Si:H thin films.The hydrogen content decreases from 18% down to 11% when increasing the gas temperature from room temperature (RT) to 433 K.Meanwhile,the clustered hydrogen at the physical film surface or at the internal surfaces of the microvoids decreases,indicating that a-Si:H thin films are densified at higher precursor gas temperatures.For a-Si:H thin films deposited at gas temperature of 433 K,the isolated silicon-hydrogen bonding configuration is predominant in the testing films.展开更多
The UV-Vis absorption and photoluminescence (PL) spectra of 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl) quinoxaline (Py), 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)-6,7-difluoroquinoxaline (F2Py) and 2,3-bis(9,9- dihexyl-9H-fluore...The UV-Vis absorption and photoluminescence (PL) spectra of 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl) quinoxaline (Py), 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)-6,7-difluoroquinoxaline (F2Py) and 2,3-bis(9,9- dihexyl-9H-fluoren-2-yl)-5,6,7,8-tetrafluoroquinoxaline (F4Py), which are fluorene molecular derivatives with conjugated structure, were investigated. For further investigation of the influences of fluorine auxochrome in fluorene molecular electroluminescent material on optoelectronic property, the elec- troluminescence (EL) characteristics of materials were studied by double-layer organic light-emitting diodes (OLEDs) using N,N'-Di-[(1-naphthalenyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPB) as a hole transporting layer (HTL) with the conventional vacuum deposition method. The results showed that the absorption and PL spectra of materials in film state red shifted with fluorine substituents in- creased in molecule configuration. The performance of OLEDs is as follows: at a bias voltage of 5 V, Py emitted a blue-green light at 508 nm with the Commission Internationale d'Eclairage (CIE) coordinates of (0.23, 0.43) and full width at half maximum (FWHM) of 100 nm. The device had a turn-on voltage (de- fined as the drive voltage at the luminance of 1 cd/m2) of 4.8 V, a luminance of 129 cd/m2 with a current density of 59 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.18 lm/W at 5.4 V. F2Py and F4Py emitted a green light peaking at 544 nm and a yellow light at 570 nm at 5 V, with the CIE coordinates of (0.38, 0.56) and (0.44, 0.49), and FWHM of 103 and 117 nm, respectively. The F2Py and F4Py devices had a turn-on voltage of 4 and 2 V, a luminance of 557 and 3300 cd/m2 with a current density of 100 and 880 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.22 lm/W at 7.6 V and 0.53 lm/W at 2 V, respectively.展开更多
Formaldehyde(HCHO),a colorless and pungent-smelling gas,is confirmed be a huge threat to human health.The detection of formaldehyde is necessary and important.The Poly(3-hexythiophene)(P3HT)/ZnO organic-inorganic comp...Formaldehyde(HCHO),a colorless and pungent-smelling gas,is confirmed be a huge threat to human health.The detection of formaldehyde is necessary and important.The Poly(3-hexythiophene)(P3HT)/ZnO organic-inorganic composite thin film was fabricated and used as the sensitive layer of organic thin film transistors(OTFT) by spray-deposited method to detect HCHO at room temperature.The process parameters such as P3HT/ZnO weight ratios and airbrushed masses were optimized.The results showed that P3HT/ZnO OTFT exhibited good sensing response to HCHO.Airbrushed mass of 1ml was the optimal mass,and the 1:1 and 1:5 weight ratios of P3HT/ZnO exhibited better sensing properties compared with others.OTFT gas sensors based on P3HT/ZnO composite film provides a novel promising approach to the detection of HCHO.展开更多
Flexible nitrogen dioxide(NO_2) gas sensors based on organic thin-film transistors(OTFTs) were developed in this work, in which conductive indium tin oxide(ITO) coated polyethylene naphthalene-2,6-dicarboxylate(PEN) w...Flexible nitrogen dioxide(NO_2) gas sensors based on organic thin-film transistors(OTFTs) were developed in this work, in which conductive indium tin oxide(ITO) coated polyethylene naphthalene-2,6-dicarboxylate(PEN) was designed for the flexible substrates, and poly methyl methacrylate(PMMA) and poly(3-hexylthiophene)(P3HT) was spin-coated as the gate dielectric layer and spray-deposited as the active layer, respectively. The effects of PMMA concentrations and P3HT solution volume on performances of flexible OTFTs were systematically investigated. The results showed that the optimized flexible OTFT exhibited high field-effect mobility(9.51×10^(–3) cm^2/(V s) at a gate bias of –50 V) and excellent response characteristics,including high sensitivity(up to 0.169 ppm^(–1)), good repeatability and selectivity. The flexibility of the developed OTFT sensor was also investigated, and the results showed that the electrical and gas-sensing properties were affected by the bending cycles,thus further work should be done for improving the flexibility of the sensor. This work provides an effective approach in developing high performance flexible OTFT NO_2 gas sensor.展开更多
文摘Inter-dune lake sediment cores are ideal and unavailable materials for study climate and environmental changes of arid region.The precious dating of lake sediment cores is required for carrying out high resolution climate and environmental changes with these cores.The Badain Jaran inter-dune lake group embedding in the sand sea is the
基金supported by the Ministry of Education of People’s Republic of China (Grant No. J2009JBPY003)
文摘Hydrogen bonding configurations and hydrogen content in hydrogenated amorphous silicon (a-Si:H) thin films prepared at different precursor gas temperatures with undiluted silane have been investigated by means of Fourier transform infrared (FTIR) spectroscopy.The results show that the gas temperature before precursor gases entering the glow-discharge zone re-markably influences the hydrogen bonding configurations and the hydrogen content in a-Si:H thin films.The hydrogen content decreases from 18% down to 11% when increasing the gas temperature from room temperature (RT) to 433 K.Meanwhile,the clustered hydrogen at the physical film surface or at the internal surfaces of the microvoids decreases,indicating that a-Si:H thin films are densified at higher precursor gas temperatures.For a-Si:H thin films deposited at gas temperature of 433 K,the isolated silicon-hydrogen bonding configuration is predominant in the testing films.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 60425101, 20674049)Program for New Century Excellent Talents in University (Grant No. NCET-06-0812)Young Excellence Project of UESTC (Grant No. 060206)
文摘The UV-Vis absorption and photoluminescence (PL) spectra of 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl) quinoxaline (Py), 2,3-bis(9,9-dihexyl-9H-fluoren-2-yl)-6,7-difluoroquinoxaline (F2Py) and 2,3-bis(9,9- dihexyl-9H-fluoren-2-yl)-5,6,7,8-tetrafluoroquinoxaline (F4Py), which are fluorene molecular derivatives with conjugated structure, were investigated. For further investigation of the influences of fluorine auxochrome in fluorene molecular electroluminescent material on optoelectronic property, the elec- troluminescence (EL) characteristics of materials were studied by double-layer organic light-emitting diodes (OLEDs) using N,N'-Di-[(1-naphthalenyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPB) as a hole transporting layer (HTL) with the conventional vacuum deposition method. The results showed that the absorption and PL spectra of materials in film state red shifted with fluorine substituents in- creased in molecule configuration. The performance of OLEDs is as follows: at a bias voltage of 5 V, Py emitted a blue-green light at 508 nm with the Commission Internationale d'Eclairage (CIE) coordinates of (0.23, 0.43) and full width at half maximum (FWHM) of 100 nm. The device had a turn-on voltage (de- fined as the drive voltage at the luminance of 1 cd/m2) of 4.8 V, a luminance of 129 cd/m2 with a current density of 59 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.18 lm/W at 5.4 V. F2Py and F4Py emitted a green light peaking at 544 nm and a yellow light at 570 nm at 5 V, with the CIE coordinates of (0.38, 0.56) and (0.44, 0.49), and FWHM of 103 and 117 nm, respectively. The F2Py and F4Py devices had a turn-on voltage of 4 and 2 V, a luminance of 557 and 3300 cd/m2 with a current density of 100 and 880 mA/cm2 at 10 V, and a maximum luminous efficiency of 0.22 lm/W at 7.6 V and 0.53 lm/W at 2 V, respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61176066,61101031)
文摘Formaldehyde(HCHO),a colorless and pungent-smelling gas,is confirmed be a huge threat to human health.The detection of formaldehyde is necessary and important.The Poly(3-hexythiophene)(P3HT)/ZnO organic-inorganic composite thin film was fabricated and used as the sensitive layer of organic thin film transistors(OTFT) by spray-deposited method to detect HCHO at room temperature.The process parameters such as P3HT/ZnO weight ratios and airbrushed masses were optimized.The results showed that P3HT/ZnO OTFT exhibited good sensing response to HCHO.Airbrushed mass of 1ml was the optimal mass,and the 1:1 and 1:5 weight ratios of P3HT/ZnO exhibited better sensing properties compared with others.OTFT gas sensors based on P3HT/ZnO composite film provides a novel promising approach to the detection of HCHO.
基金supported by the Funds for Creative Research Groups of China(Grant No.61421002)the National Natural Science Foundation of China(Grant Nos.61571097 and 61604033)the National Postdoctoral Program for Innovative Talents(Grant No.BX201600026)
文摘Flexible nitrogen dioxide(NO_2) gas sensors based on organic thin-film transistors(OTFTs) were developed in this work, in which conductive indium tin oxide(ITO) coated polyethylene naphthalene-2,6-dicarboxylate(PEN) was designed for the flexible substrates, and poly methyl methacrylate(PMMA) and poly(3-hexylthiophene)(P3HT) was spin-coated as the gate dielectric layer and spray-deposited as the active layer, respectively. The effects of PMMA concentrations and P3HT solution volume on performances of flexible OTFTs were systematically investigated. The results showed that the optimized flexible OTFT exhibited high field-effect mobility(9.51×10^(–3) cm^2/(V s) at a gate bias of –50 V) and excellent response characteristics,including high sensitivity(up to 0.169 ppm^(–1)), good repeatability and selectivity. The flexibility of the developed OTFT sensor was also investigated, and the results showed that the electrical and gas-sensing properties were affected by the bending cycles,thus further work should be done for improving the flexibility of the sensor. This work provides an effective approach in developing high performance flexible OTFT NO_2 gas sensor.
