Device Applications of Direct Gap Group IV Semiconductors

Group IV Direct Band Gap Photonics: Methods, Challenges, and Opportunities

The concept of direct band gap group IV materials may offer a paradigm change for Si-photonics concerning the monolithic implementation of light emitters: the idea is to integrate fully compatible group IV materials with equally favorable optical properties as the chemically incompatible group III–V-based systems. The concept involves either mechanically applied strain on Ge or alloying of Ge w...

Computing Device Applications of Group IV Nanoparticle Spectroscopy

Nonmonotonic decay of nonequilibrium polariton condensate in direct-gap semiconductors.

Time evolution of a nonequilibrium polariton condensate has been studied in the framework of a microscopic approach. It has been shown that due to polariton-polariton scattering a significant condensate depletion takes place in a comparatively short time interval. The condensate decay occurs in the form of multiple echo signals. Distribution-function dynamics of noncondensate polaritons have be...

Extremely nondegenerate two-photon absorption in direct-gap semiconductors [Invited].

Two-photon absorption (2PA) spectra with pairs of extremely nondegenerate photons are measured in several direct-gap semiconductors (GaAs, CdTe, ZnO, ZnS and ZnSe) using picosecond or femtosecond pulses. In ZnSe, using photons with a ratio of energies of ~12, we obtain a 270-fold enhancement of 2PA when comparing to the corresponding degenerate 2PA coefficient at the average photon energy (ηω1 ...

Narrow-Gap Semiconductors and Low-Dimensional Structures for Optoelectronic Applications

Advances in the growth, analysis, and characterization of various narrow-gap semiconductors and low-dimensional opto-electronic device structures have brought revolution into the modern day's information and communication technology including optical communication and computing systems. The main objective of this special issue is to include the recent advances in the experimental and theoretica...