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Fabrication and optical properties of InGaN/GaN multiple quantum well light emitting diodes with amorphous BaTiO3 ferroelectric film 下载免费PDF全文
BaTiO3 (BTO) ferroelectric thin films are prepared by the sol,el method. The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode (LED) with amorphous BTO ferroelectric thin film are studied. The photolumineseence (PL) of the BTO ferroelectric film is attributed to the structure. The ferroeleetric film which annealed at 673 K for 8 h has the better PL property. The peak width is about 30 nm from 580 nm to 610 nm, towards the yellow region. The mixed electroluminescence (EL) spectrum of InGaN/GaN multiple quantum well LED with 150-nm thick amorphous BTO ferroelectric thin film displays the blue-white light. The Commission Internationale De L'Eclairage (CIE) coordinate of EL is (0.2139, 0.1627). EL wavelength and intensity depends on the composition, microstructure and thickness of the ferroelectric thin film. The transmittance of amorphous BTO thin film is about 93% at a wavelength of 450 nm-470 nm. This means the amorphous ferroelectrie thin films can output more blue-ray and emission lights. In addition, the amorphous ferroelectric thin films can be directly fabricated without a binder and used at higher temperatures (200 ℃-400 ℃). It is very favourable to simplify the preparation process and reduce the heat dissipation requirements of an LED. This provides a new way to study LEDs. 相似文献
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Fabrication and optical properties of InGaN/GaN multiple quantum well light emitting diodes with amorphous BaTiO<sub>3</sub> ferroelectric film 下载免费PDF全文
BaTiO3(BTO) ferroelectric thin films are prepared by the sol-gel method.The fabrication and the optical properties of an InGaN/GaN multiple quantum well light emitting diode(LED) with amorphous BTO ferroelectric thin film are studied.The photoluminescence(PL) of the BTO ferroelectric film is attributed to the structure.The ferroelectric film which annealed at 673 K for 8 h has the better PL property.The peak width is about 30 nm from 580 nm to 610 nm,towards the yellow region.The mixed electroluminescence(EL) spectrum of InGaN/GaN multiple quantum well LED with 150-nm thick amorphous BTO ferroelectric thin film displays the blue-white light.The Commission Internationale De L’Eclairage(CIE) coordinate of EL is(0.2139,0.1627).EL wavelength and intensity depends on the composition,microstructure and thickness of the ferroelectric thin film.The transmittance of amorphous BTO thin film is about 93% at a wavelength of 450 nm-470 nm.This means the amorphous ferroelectric thin films can output more blue-ray and emission lights.In addition,the amorphous ferroelectric thin films can be directly fabricated without a binder and used at higher temperatures(200℃-400℃).It is very favourable to simplify the preparation process and reduce the heat dissipation requirements of an LED.This provides a new way to study LEDs. 相似文献
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本文给出了维O-U型马氏过程像集的Housdorff维数上下界的一个估计,并研究了两个独立的一维O-U型马氏过程的碰撞问题。 相似文献
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Yamamuro in [1] defines strong and weak transience of Markov processes; gives a criterion for strong transience of Feller processes; and further, discusses strong and weak transience of Ornstein-Uhlenbeck type processes. In this article, the authors weaken the Feller property of the result in [1] to weak Feller property and discuss the strong transience of operator-self-similar Markov processes. 相似文献
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考虑一类稀疏过程下索赔相依的两险种风险模型:U(t)=u+ct-∑i=1N2(t)X_i-∑i=1N2(t)Y_(i),其中{N_1(t),t≥0}、{N_2(t),t≥0}分别表示两个险种的索赔次数,它们按下述方式相关:N_1(t)N_(11)(t)+N_(12)(t),N_2(t)=N_(22)(t)+N'_(12)(t),{N'_(12)(t),t≥0}是{N_(12)(t),t≥0}的一个p-稀疏.考虑下列两种情形:(Ⅰ){N_(11)(t),t≥0}、{N_(12)(t),t≥0}、{N_(22)(t),t≥0}均为Poisson过程;(Ⅱ){N_(11)(t),t≥0}、{N_(22)(t),t≥0}为Poisson过程,{N_(12)(t),t≥0}为Erlang(2)过程.在上述两种情形下,当两险种的单次索赔额均服从指数分布时,通过建立并求解生存概率所满足的微分方程,给出其破产概率的表达式. 相似文献
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本文研究自相似马氏过程的碰撞,利用两个α-自相似马氏过程的耦合,获得了两个α-自相似马氏过程发生碰撞的一个充分条件,并且,在任何有限的时间内,两个α-自相似马氏过程将以正概率发生不可列无穷多次的碰撞. 相似文献
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