A CO_2 laser rapid-thermal-annealing SiO_x based metal-oxide-semiconductor light emitting diode

Enhanced near-infrared (NIR) electroluminescence (EL) of a metal-oxide-semiconductor light emitting device (MOSLED) made on CO_2 laser-annealed SiO_x film is demonstrated.An EL power of near 50 nW from CO_2 laser rapid-thermal-annealing (RTA) MOSLED under a biased voltage of 85 V and a current density of 2.3 mA/cm~2 is preliminarily reported.     

Annealing induced refinement on optical transmission and electrical resistivity of indium tin oxide

The effect of annealing condition on sputtered indium tin oxide （ITO） films on quartz with the thickness of 200 nm is characterized to show enhanced optical transparency and optimized electrical contact resistivity. The as-deposited grown ITO film exhibits only 65% and 80% transmittance at 532 and 632.8 nm, respectively. After annealing at 475 ℃ for 15 min, the ITO film is refined to show improved transmittance at shorter wavelength region. The transmittances of 88.1% at 532 nm and 90.4% at 632.8 nm can be obtained. The 325-nm transmittance of the post-annealed ITO film is greatly increased from 12.7% to 41.9%. Optimized electrical property can be obtained when annealing below 450 ℃, leading to a minimum sheet resistance of 26 Ω/square. Such an ITO film with enhanced ultraviolet （UV） transmittance has become an alternative candidate for applications in current UV photonic devices. The morphology and conductance of the as-deposited and annealed ITO films are determined by using an atomic force microscopy （AFM）, showing a great change on the uniformity distribution with finite improvement on the surface conductance of the ITO film after annealing.     

光注入弱谐振腔法布里-珀罗激光器非线性动力学特性的实验研究

实验研究了弱谐振腔法布里-珀罗激光器在受到光注入扰动时的非线性动力学特性.通过测定"-3模"、"0模"、"13模"三个纵模输出的时间序列,功率谱和光谱分布,对其非线性动力学状态进行了判定.研究结果表明:引入光注入后,通过改变注入强度及频率失谐,这三个纵模均可呈现出四波混频、单周期态、准周期态、混沌态以及稳定的光注入锁定态等非线性动力学特性,其动力学演化路径为经准周期分岔进入混沌态.此外,为实现对动力学状态的精确控制,绘制了这三个纵模在光注入强度0μW到450μW和频率失谐-16GHz到16GHz构成的参量空间的动力学状态分布图.结果显示:"0模"与"13模"在正、负频率失谐均可观察到混沌区域,而"-3模"在负频率失谐没有出现混沌区域;"0模"存在两个分离的稳定的光注入锁定态区,而在"-3模"和"13模"仅观测到一个稳定的光注入锁定态区.     

Luminescent-wavelength tailoring silicon-rich silicon nitride LED

Wavelength tunable photoluminescence （PL） of Si-rich silicon nitride （SRSN） film with buried Si nanocrystals （Si-ncs） grown by plasma enhanced chemical vapor deposition （PECVD） under Sill4 and NH3 environment is investigated. Intense broadband visible emissions tunable from blue to red can be obtained from the as-deposited SiNs thin films with increasing NH3 flow rate from 150 to 250 sccm and detuning the SiH4/NH3 flow ratio during deposition. To date, the normalized PL wavelength of SiNx films after anneal- ing could be detuned over the range of 385-675 nm by decreasing the NH3 flow rate, corresponding to an enlargement on Si-nc size from 1.5-2 to 4-5 nm. The PL linewidth is decreased with increasing ammonia flow rate due to the improved uniformity of Si-ncs under high NH3 flow rate condition. In addition, the PL intensity is monotonically increasing with the blue shift of PL wavelength due to the increasing density of small-size Si-ncs. The ITO/SiNx/p-Si/Al diode reveals highly resistive property with the turn-on voltage and power-voltage slope of only 20 V and 0.18 nW/V, respectively. The turn-on voltage can further reduce from 20 to 3.8 V by improving the carrier injection efficiency with p-type Si nano-rods.     

利用较完善模型研究半导体光放大器对皮秒光脉冲的放大

提出了一个描述半导体光放大器（SLA）对皮秒脉冲的放大这一物理过程的较为完善的物理模型，并数值分析了光脉冲经SLA放大后的上升时间和下降时间.结果表明：随着SLA偏置电流的增大，上升时间将缩短而下降时间将延长；输入脉冲的大峰值功率将加速上升时间的缩短和下降时间的延长；增益压缩对脉宽为几个皮秒的输入脉冲的上升时间和下降时间有明显的影响，而对脉宽为几十皮秒的输入脉冲可近似认为没有影响；增益非对称和漂移强烈影响上升和下降时间. 关键词： 半导体光放大器 皮秒光脉冲 上升和下降时间     

Enhanced electroluminescence from nanocrystallite Si based MOSLED by interfacial Si nanopyramids

The interfacial Si nano-pyramid-enhanced electroluminescence (EL) of an ITO/SiO_x/p-Si/A1 metal-oxide- semiconductor (MOS) diode with turn-on voltage of 50 V,threshold current of 1.23 mA/cm~2,output power of 16 nW,and lifetime of 10 h is reported.