Ultrafast Carrier Transport, Screening and Space-Charge Field Formation in Semiconductors

项目负责人：Arthur L. Smirl“半导体中的超快载流子输运、筛选和空间电荷场形成”摘要：将对半导体结构中的载流子动力学和空间电荷形成进行综合研究。未来的光子和电子系统，以及两者之间的互连，将依赖于并受限于在微米和纳米尺寸上控制载流子传输的能力，以及对伴随这种传输的空间电荷形成、筛选和光学性质变化的理解。五个相互关联的研究任务将构成研究的主体：(1)测量四波混频信号的时间分辨Stokes参数，研究多量子阱中激子-激子相互作用和载流子散射；(2)发展灵敏的新技术来测量由弹道输运引起的相干等离子体振荡。这些测量预计将提供以任何其他方式无法获得的有关输运/散射过程的信息；(3)测量“堆叠种子”电光调制器结构的每伏特电光和每载流子非线性光学响应；(4)应变压电多量子阱的输运、筛选和电光响应研究；(5)利用超快技术测量/量化光生载流子的动力学、空间电荷场的形成和光开关谐振隧道二极管的隧穿时间。

Proposal Number: ECS-9528854 Principal Investigator: Arthur L. Smirl "Ultrafast carrier transport, screening and space-charge field formation in semiconductors" ABSTRACT Comprehensive studies of carrier dynamics and space-charge formation in semiconductor structures will be performed. Future photonic and electronics systems, and interconnects between the two, will rely on and be limited by the ability to control carrier transport over micron and nanometer sized dimensions and by an understanding of the space-charge formation, screening and changes in optical properties that accompany such transport. Five interrelated research tasks will form the main body of the research (1) measurement of time-resolved Stokes parameters for the four-wave mixing signal to study exciton-exciton interactions and carrier scattering in multiple quantum wells; (2) development of sensitive new techniques to measure coherent plasma oscillations which results from ballistic transport. These measurements are expected to provide information about transport/scattering processes which cannot be obtained in any other way; (3) measurement of the per volt electro-optic and per carrier nonlinear optical responses of "stacked SEEDs" electro-optic modulator structures; (4) investigation of the transport, screening and electro-optic response of strained piezo-electric multiple quantum wells; and (5) use of ultrafast techniques to measure/quantify the dynamics of photogenerated carriers, space-charge field formation and the tunneling times in optically switched resonant tunneling diodes.