Engineering topics

Noriega, O. C.

Publications and source records attributed to Noriega, O. C..

2 records

DOE OSTI2017

Determining and Controlling the Magnesium Composition in CdTe/CdMgTe Heterostructures

The relationships between Mg composition, band gap, and lattice characteristics are investigated for Cd 1-x Mg x Te barrier layers using a combination of cathodoluminescence, energy dispersive x-ray spectroscopy, variable angle spectral ellipsometry, and atom probe tomography. The use of a simplified, yet accurate, variable angle spectral ellipsometry analysis is shown to be appropriate for fast determination of composition in thin Cd 1-x Mg x Te layers. The validity of using high-resolution x-ray diffraction for CdTe/Cd 1-x Mg x Te double heterostructures is discussed. Furthermore, the stability of CdTe/Cd 1-x Mg x Te heterostructures are investigated with respect to thermal processing.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2014

Radiative and interfacial recombination in CdTe heterostructures

Double heterostructures (DH) were produced consisting of a CdTe film between two wide band gap barriers of CdMgTe alloy. A combined method was developed to quantify radiative and non-radiative recombination rates by examining the dependence of photoluminescence (PL) on both excitation intensity and time. The measured PL characteristics, and the interface state density extracted by modeling, indicate that the radiative efficiency of CdMgTe/CdTe DHs is comparable to that of AlGaAs/GaAs DHs, with interface state densities in the low 1010 cm−2 and carrier lifetimes as long as 240 ns. The radiative recombination coefficient of CdTe is found to be near 10−10 cm3s−1. CdTe film growth on bulk CdTe substrates resulted in a homoepitaxial interface layer with a high non-radiative recombination rate.

Swartz, C. H.↗