Shanghai Juntech Co.

Shanghai, China

Shanghai Juntech Co.

Shanghai, China
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Xu B.,Tianjin University | Xu B.,Chang Gung University | Dai H.T.,Tianjin University | Wang S.G.,Tianjin University | And 6 more authors.
International Journal of Photoenergy | Year: 2014

We investigated the effects of pre-TMIn treatment on the optical properties of green light emitting diodes (LEDs). Although pre-TMIn treatment did not affect the epitaxial structure of quantum wells, it significantly improved the quality of the surface morphology relative to that of the untreated sample. Indium cluster can be seen by high-resolution transmission electron microscopy (HR-TEM), which is the explanation for the red-shift of photoluminescence (PL). Time-resolved photoluminescence measurements indicated that the sample prepared with pre-TMIn treatment had a shorter radiative decay time. As a result, the light output power of the treated green LED was higher than that of the conventional untreated one. Thus, pre-TMIn treatment appears to be a simple and efficient means of improving the performance of green LEDs. © 2014 Bing Xu et al.

Wang Y.,University of Electronic Science and Technology of China | Tang W.,University of Electronic Science and Technology of China | Zhang L.,Xi'an Jiaotong University | Zhao J.,Shanghai Juntech Co.
Thin Solid Films | Year: 2014

Ga-doped ZnO (GZO) thin films were deposited on glass substrates by a radio frequency magnetron sputtering technique. The optical properties of the deposited GZO films were evaluated using an optical transmission measurement. The optical band gap increased from 3.32 eV to 3.45 eV with the increasing carrier density from 2.0 × 1020 cm- 3 to 3.24 × 1020 cm- 3. Based on the experimental results, the optical band gap as a function of carrier density is systematically investigated with four available theoretical models taken into consideration. The blueshift of the optical band gap in GZO films can be well interpreted with a complex model which combines the Burstein-Moss effect, the band gap renormalization effect and the nonparabolic nature of conduction band. In addition, the BM contribution is almost offset by the BGR effect in both conduction band and valence band due to the approximate equality between electron and hole effective masses in GZO films with a nonparabolic conduction band. The tunability of optical band gap in GZO thin films by carrier density offers a number of potential advantages in the development of semiconductor optoelectronic devices. © 2014 Elsevier B.V. All rights reserved.

Tang L.,Tianjin University | Zhao J.,Tianjin University | Zhao J.,Shanghai Juntech Co. | Zhang X.,Tianjin University | And 2 more authors.
Micro and Nano Letters | Year: 2014

The effects of the molybdenum trioxide (MoO3) intermediate layer on the performance of all-inorganic colloidal quantum dot light-emitting diodes (QD-LEDs) with a structure of ITO/MoO3/NiO/QDs/ZnO/Al are explored. MoO3 layers with different thickness were inserted between the indium tin oxide and nickel oxide layer via a thermal evaporation process. The presented results show that an ultrathin ( ∼ 5 nm) MoO3 intermediate layer significantly enhanced the electroluminescence (EL) intensity of the QD-LED, which was more than 100 times higher than the device without the MoO3 layer. It is suggested that the EL enhancement originates from the effectively facilitated injection of holes into quantum dots through the MoO3 intermediate layer. © The Institution of Engineering and Technology 2014.

Zhang X.,Tianjin University | Li Y.,Tianjin University | Zhao J.,Shanghai Juntech Co. | Wang S.,Tianjin University | And 2 more authors.
Journal of Power Sources | Year: 2014

In this work, Ag nanoparticles as co-catalysts are employed to modify the nanoscale ZnO/CdS interface to achieve a ZnO/Ag/CdS nanocomposite photoanode for photocatalytic water splitting. The three-component photoanode exhibits significantly enhanced photoelectrochemical properties as compared with the single-component (ZnO) and two-component (ZnO/Ag or ZnO/CdS) systems. The modification with Ag nanoparticles can significantly enhance the light absorption and facilitate the separation and transport of photogenerated carriers through the localized surface plasma resonance (LPSR) effect. The developed ZnO/Ag/CdS nanocomposite photoanode presents significantly improved water splitting performance, with a high hydrogen productivity up to 3.5 mL h-1 (∼155 umol h-1) at + 0.4 V vs. Ag/AgCl electrode with an almost constant rate during 10 h. Even without any external bias, the photoanode can still exhibit a relatively high hydrogen productivity up to 0.5 mL h-1. Furthermore, the nanocomposite photoanode shows excellent photocorrosion resistance, which is ascribed to a considerable decrease of surface defect density on ZnO nanowires and the reduction of holes. © 2014 Elsevier B.V. All rights reserved.

Xu X.-K.,CAS Shanghai Institute of Ceramics | Xu X.-K.,Shanghai Juntech Co. | Zhao J.-L.,Shanghai Juntech Co. | Zhao J.-L.,Tianjin University | And 4 more authors.
Gongneng Cailiao/Journal of Functional Materials | Year: 2015

Transparent conductive B doped ZnO (BZO) film grown by low pressure chemical vapor deposition (LPCVD) has been emerging as an efficient light scattering front electrode for thin film silicon solar cells. In the study, high quality BZO films were grown on glass substrates by LPCVD using Zn(C2H5)2, H2O as precursors and B2H6 as the dopant. The crystalline structure, morphology and electrical properties were characterized by X-ray diffraction (XRD), field-emitting scanning electron microscope (FESEM) and four-probe method. The results show that the thinner films (<500 nm) exhibit (002) preferred orientation, while the crystal orientation evolves to (110) with the increase of film thickness.The BZO coated glasses exhibit high transmittance (about 80%) in the visible and near-infrared range, and the (110) oriented BZO films present significant diffusive transmittance with the haze (at 550 nm) up to 28%.The BZO films with sufficient thickness show good conductivity with sheet resistance down to about 7 Ω/□ and resistivity down to about 1.0×10-3Ω·cm. ©, 2015, Journal of Functional Materials. All right reserved.

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