高温退火对MgO晶体光致发光性能的影响

利用自行搭建的实验平台,测试了高纯MgO晶体和Sc掺杂MgO晶体的紫外光光致发光(PL)光谱,发射峰值分别位于389.31、498.61nm、712.44和749.06nm,其可见光发射区和红外发射区主要对应于MgO晶体中由O空位构成的F色心和F+色心通过激发和退激发机制发射;在不同温度退火条件下测试Sc掺杂MgO晶体的PL光谱,并利用高斯分解实现了Sc掺杂MgO晶体中F色心和F+色心的定位。结果表明,高温退火处理可以有效降低MgO晶体表面的污染,进而提高晶体的光电活性;Sc掺杂导致MgO晶体可见光发射区域的蓝移和增强,其中F+色心对于温度的依赖性较强。     

非对称耦合双量子点中激子的动力学行为

利用二能级近似理论分析了外场驱动下非对称耦合双量子点中激子的动力学行为，并给出了局域化的条件．分析发现：当外场振幅较小时，库仑相互作用扮演着重要角色，激子的动力学行为主要发生在低能级子空间，场强和频率之比是Bessel方程的根时，准能发生回避交叉，激子的局域化现象发生．随着外场振幅增大，激子解体，电子和空穴可以独立在量子点之间隧穿．借助于Floquet理论，进行了数值计算，计算结果与理论分析相符．     

二氯一氟甲烷多光子解离浓集氘的参数影响

本文使用自制TEACO_2激光器研究了二氯一氟甲烷多光子解离浓集氘时,诸如激光波长、脉冲能量、能流密度,氘化组分的压力等参数的影响,并指出了影响过程的可能机理。     

非对称耦合双量子点中激子的动力学行为

利用二能级近似理论分析了外场驱动下非对称耦合双量子点中激子的动力学行为,并给出了局域化的条件.分析发现:当外场振幅较小时,库仑相互作用扮演着重要角色,激子的动力学行为主要发生在低能级子空间,场强和频率之比是Bessel方程的根时,准能发生回避交叉,激子的局域化现象发生.随着外场振幅增大,激子解体,电子和空穴可以独立在量子点之间隧穿.借助于Floquet理论,进行了数值计算,计算结果与理论分析相符.     

工作温度对硅基太阳电池转换效率的影响

基于wxAMPS软件建立硅基太阳电池一维物理模型,在温控条件下分别模拟计算了单晶硅电池和非晶硅电池的输出特性,并利用太阳能综合测试平台在温控条件下测试了单晶硅和非晶硅电池的输出特性.模拟结果表明非晶硅电池在温度升高过程中的光电转换效率下降幅度显著降低,与实验结果吻合.     

Temperature-controllable spin-polarized current and spin polarization in a Rashba three-terminal double-quantum-dot device

We propose a Rashba three-terminal double-quantum-dot device to generate a spin-polarized current and manipulate the electron spin in each quantum dot by utilizing the temperature gradient instead of the electric bias voltage. This device possesses a nonresonant tunneling channel and two resonant tunneling channels. The Keldysh nonequilibrium Green's function techniques are employed to determinate the spin-polarized current flowing from the electrodes and the spin accumulation in each quantum dot. We find that their signs and magnitudes are well controllable by the gate voltage or the temperature gradient. This result is attributed to the change in the slope of the transmission probability at the Fermi levels in the low-temperature region. Importantly, an obviously pure spin current can be injected into or extracted from one of the three electrodes by properly choosing the temperature gradient and the gate voltages. Therefore, the device can be used as an ideal thermal generator to produce a pure spin current and manipulate the electron spin in the quantum dot.     

Dynamical Localization in an Asymmetric Two-Electron Quantum Dot Molecule by an Alternating-Current Electric Field

We investigate the dynamics of two interacting electrons in an asymmetric double coupled quantum dot under an ac electric field. The numerical results demonstrate that dynamical localization and Rabi oscillation still exist in such a system under the stronger electron correlation. The two electrons can be regarded as a quasiparticle, which move together between two dots similarly to a boson. The dynamics of two electrons in such a quantum system are mainly confined in a Q subspace, which is constructed by two double-occupied states.     

在分子束中SF_6分子单频和双频红外多光子离解谱

在分子束中做了SF_6分子的单频和双频红外多光子离解(MPD)谱,研究了分子转振温度和激光能流对MPD的影响。把实验结果和理论计算结果做了比较分析,认为双光子和叁光子共振跃迁统治了这些离解谱的结构。     

自由空间光通信技术及其发展

自由空间光通信(FSO)又称无线光通信,是指以激光为载波,在真空或大气中传递信息的通信技术.文章主要介绍了自由空间光通信的优势、特点以及存在的问题,并分析了自由空间光通信在未来的发展方向.