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17 results on '"Han, Jin-ru"'

11. Effect of reduction-slagging coupling of Cr2O3during in-situ preparation of homogeneous CuCr50 alloy by self-propagating high temperature synthesis metallurgy

Author

Han, Jin-ru, Dou, Zhi-he, Zhang, Ting-an, and An, Wang

Abstract

The high-efficiency separation of alloy and slag is fundamental to obtain high-performance CuCr alloys by self-propagating high temperature synthesis metallurgy. In this paper, Cr2O3can determine the basic composition of CuCr alloy through the reduction efficiency, and also participates in the slagging process, which determines the separation effect of slag and alloy. Therefore, the reduction behavior and slagging effect of Cr2O3during the in-situ synthesis of CuCr alloy by aluminothermic reduction is investigated. The results show that the Cr content of the prepared CuCr alloy is 41.3 wt.%∼42.0 wt.% according to the theoretical stoichiometric ratio, and the Cr2O3content in the slag is 16.2 wt.%∼17.0 wt.%. When the Cr2O3dosage is 50% over the theoretical stoichiometric ratio, the Cr content of the prepared CuCr alloy and the Cr2O3content in the slag increases to 47.0%∼47.6 wt.% and 28.4 wt.%∼29.2 wt.%, respectively. With the increase of Cr2O3dosage in the ingredients, the effect of alloy-slag separation is better, the inclusion in the alloy changes from Al2O3inclusion to Cr2O3inclusion, and the relative density of prepared CuCr alloy increases from 90.9% to 98.5%. The overall composition is evenly distributed among the different parts of the alloy. The conductivity of CuCr alloy reaches 15.69 MS m−1, and hardness reaches 95.1 H B.

Published
2022
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14. Study of light efficiency and lifetime of LED with different surface structures

Author

Chen Yi-Xin, Shen Guang-di, Li Jianjun, Guo Weiling, and Han Jin-Ru

Subjects
Light intensity, Materials science, business.industry, Saturation current, Heat generation, General Physics and Astronomy, Optoelectronics, Surface structure, Surface finish, Current (fluid), business, Epitaxy, Accelerated aging
Abstract

The main problem of GaAs based AlGaInP series LED is the low light extraction efficiency and heat generation inside, which have serious impact on the LED' lifetime. In this paper, we introduce a kind of LED with new surface structure formed of surface texture and light anti-reflecting layers through the post-epitaxial processing. In this new structure, the inside light transmission route has been changed and the current spreading is enhanced, which makes much more light emit outside. With the same injected current, the new LED' output light intensity is in average 15 times as the normal LED with the same epitaxial structure, and the ratio is larger than 15 as the injected current increases. The new LED's saturation current is as high as 125 mA because of the heat is decreased inside, the accelerated aging test shows that the new LED' lifetime is as long as 13×104 h for packaged ones and 19×104 h for unpackaged ones, which is suitable for working at large injected current especially.

Published
2010

15. AlGaInP LEDs with surface anti-reflecting structure

Author

Han Jin-Ru, Shen Guang-di, Li Jian-Jun, Xu Chen, and Chen Yixin

Subjects
Surface (mathematics), Materials science, Light extraction in LEDs, business.industry, Luminous intensity, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Optics, Saturation current, law, Materials Chemistry, Optoelectronics, Quantum efficiency, Electrical and Electronic Engineering, business, Light-emitting diode
Abstract

A kind of AlGaInP light emitting diode (LED) with surface anti-reflecting structure has been introduced to solve the problems of low light efficiency and restricted luminous intensity. The new structure can be demonstrated theoretically and experimentally, and LEDs with the new structure have higher on-axis luminous intensity and larger saturation current than conventional LEDs and LEDs with ITO film only, which is caused by higher external quantum efficiency and also higher internal quantum efficiency. The new LEDs are especially suitable for working at large injected currents.

Published
2009

17. Large optical cavity and small vertical divergence angle semiconductor lasers

Author

Liu Ying, Han Jin-Ru, Shen Guang-di, Li Jian-Jun, Wang Dong-Feng, Zhao Hui-Min, Cui Bi-Feng, Du Jinyu, Zou De-Shu, and Lian Peng

Subjects
Optical amplifier, Catastrophic optical damage, Materials science, business.industry, Slope efficiency, Physics::Optics, General Physics and Astronomy, Laser, law.invention, Semiconductor laser theory, Optics, law, Optical cavity, Optoelectronics, Semiconductor optical gain, business, Tunable laser
Abstract

A novel coupled large optical cavity cascaded by tunnel-junction semiconductor lasers is put forward to resolve the major difficulties of ordinary laser diodes. In this structure several active regions are cascaded by tunnel junctions to couple a large optical cavity. This structure can solve the problem of catastrophic optical damage of facet and large vertical divergence caused by thin emitting area in ordinary laser diodes. The near-field facalur size reaches 1μm. Low-pressure metal-organic chemical vapor deposition is adopted to grow the novel semiconductor lasers. Slope efficiency as high as 0.80W/A per facet and vertical divergence angle of 20°and threshold current density of 277 A/cm2 are achieved from an uncoated novel laser device.

Published
2004

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