Optical absorption spectrum in disordered semiconductor multilayers

Maximum statistical increase of optical absorption in textured semiconductor films.

Complete statistical randomization of the direction of propagation of light trapped in semiconductor films can result in a large absorption enhancement. We have employed a calorimetric technique, photothermal deflection spectroscopy, to monitor the absorption of alpha-SiH(x) films textured by the natural lithography process. The observed enhancement factors, as high as 11.5, are consistent with...

Crystallization and melting in metal-semiconductor multilayers.

The amorphous-to-microcrystalline phase transition of Ge in Pb/Ge multilayer geometry has been investigated as a function of layer thicknesses with the use of high-temperature x-raydiA'raction techniques. During crystallization, the modulation structure is destroyed and the Pb texture improves. In addition, the crystallization temperature decreases with decreasing amorphous Ge thickness and inc...

Propagation of Light in Disordered Semiconductor Materials

Interlayer transport in disordered semiconductor electron bilayers.

We study the effects of disorder on the interlayer transport properties of disordered semiconductor bilayers by performing self-consistent quantum transport calculations. We find that the addition of material disorder to the system affects the interlayer interactions leading to significant deviations in the interlayer transfer characteristics. In particular, we find that disorder decreases and...

Photon Echoes in Disordered Semiconductor Quantum Wells

Photon echoes occur when a set of inhomoge-neously broadened transitions are rephased after exci-tation by a series of optical pulses. They are the optical analog to spin echoes developed in nuclear magnetic resonance spectroscopy [1]. The primary uses of pho-ton echoes are in coherent transient signal processing and spectroscopy. Due to the rephasing, photon echo spectroscopy can determine the...