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

建议编号：ECS-9528854首席研究员：Arthur L.Smirl“半导体中的超快载流子传输、屏蔽和空间电荷场形成”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全面研究。未来的光子和电子系统，以及两者之间的互连，将依赖于控制微米和纳米尺寸载流子传输的能力，并受到这种能力的限制，以及对伴随这种传输而来的空间电荷形成、屏蔽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斯托克斯参数，以研究激子-激子相互作用和多量子阱中的载流子散射；(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。这些测量有望提供有关输运/散射过程的信息，这些信息无法以任何其他方式获得；(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的非线性光学响应；(4)研究应变压电多量子阱的输运、屏蔽和电光响应；以及(5)利用超快技术测量/量化光开关共振隧道二极管中光生载流子、空间电荷场的形成和隧道时间的动力学。

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.