Free-Carrier Absorption And Saturation Of Intervalence-Band Transitions In P-Type Semiconductor Quantum Wells

AbstractWe report the investigation of free-carrier absorption characteristics for epitaxially grown p-type thin films in the far-infrared region (50 ∼ 200 μm), where homojunction interfacial workfunction internal photoemission (HIWIP) detectors are employed. Five Si and three GaAs thin films were grown by MBE over a range of carrier concentrations, and the experimental absorption data were compared with calculated results. The freehole absorption is found to be almost independent of the wavelength. A linear regression relationship between the absorption coefficient and the carrier concentration, in agreement with theory, has been obtained and employed to calculate the photon absorption probability in HIWIP detectors. The detector responsivity follows the quantum efficiency predicted by concentration dependence of the free carrier absorption coefficient.

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Free Carrier Absorption due to Dislocation Scattering in GaN Quantum Wells

10.1063/1.3646783 ◽

2011 ◽

Cited By ~ 1

Author(s):

R. G. Vaidya ◽

N. S. Sankeshwar ◽

B. G. Mulimani ◽

P. Predeep ◽

Mrinal Thakur ◽

...

Keyword(s):

Quantum Wells ◽

Free Carrier ◽

Free Carrier Absorption ◽

Carrier Absorption

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ON THE POSSIBILITY OF AN INTERSUBBAND LASER IN SILICON-ON-INSULATOR

International Journal of High Speed Electronics and Systems ◽

10.1142/s0129156406003746 ◽

2006 ◽

Vol 16 (02) ◽

pp. 411-420

Author(s):

SERGE LURYI ◽

ALEX ZASLAVSKY

Keyword(s):

Quantum Wells ◽

Lateral Diffusion ◽

Optical Loss ◽

Free Carrier ◽

Silicon On Insulator ◽

Free Carrier Absorption ◽

Loss Mechanism ◽

Polysilicon Gate ◽

Carrier Absorption ◽

Intersubband Relaxation

As thin Si quantum wells with oxide barriers have become an experimental reality in silicon-on-insulator technology, we discuss the feasibility of a terahertz laser based on an intersubband transition in such a Si quantum well. Electrons tunnel into an upper two-dimensional subband from a thin polysilicon gate through an ultrathin tunneling oxide and are extracted laterally from the Si well by diffusion. Population inversion arises because lateral diffusion to the contacts can be a faster process than intersubband relaxation and also because the in-plane diffusivity in the upper subband is suppressed by the interaction with a nearby subband characterized by a heavy in-plane mass. Thick oxide layers provide optical confinement and the main optical loss mechanism is the weak free-carrier absorption in thin doped regions in the polysilicon gate and substrate. A voltage on the substrate may provide some tunability of the gain peak.

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