Search results for "indium"

Polarization phenomena in Al/p-CdTe/Pt X-ray detectors

2013

Over the last decades, CdTe detectors are widely used for the development of room temperature X-ray and gamma ray spectrometers. Typically, high resolution CdTe detectors are fabricated with blocking contacts (indium, aluminum) ensuring low leakage currents and high electric field for optimum charge collection. As well known, time instability under bias voltage (termed as polarization) is the major drawback of CdTe diode detectors. Polarization phenomena cause a progressive degradation of the spectroscopic performance with time, due to hole trapping and detrapping from deep acceptors levels. In this work, we studied the polarization phenomenon on new Al/p-CdTe/Pt detectors, manufactured by …

High resolution spectroscopy of rydberg states in indium I

1985

Two-photon laser spectroscopy in a dense indium vapour allowed to investigatenp2P1/2, 3/2 states (n=27–35) for113, 115In with a thermionic diode. Precise data on the fine structure splitting of these states and the isotope shift of the two photon transitions have been obtained. The fine structure splitting shows a hydrogenic behaviour. By using the result of our isotope shift measurement in combination with literature values, level isotope shifts with reference to the ionization limit are deduced and analysed with respect to the different contributions.

Investigation of nitrogen-related acceptor centers in indium selenide by means of photoluminescence: Determination of the hole effective mass

1997

In this work we report on steady-state and time-resolved photoluminescence (PL) measurements in nitrogen-doped p-type indium selenide in the 33--210-K temperature range. In samples with low nitrogen concentration the photoluminescence spectrum consists of exciton-related peaks and a band-to-acceptor recombination peak (2.1-\ensuremath{\mu}s lifetime) with LO-phonon replica. An ionization energy of 65.5 meV is proposed for the nitrogen-related acceptor. A long-lived (18 \ensuremath{\mu}s) component, which consists of an asymmetric broadband centered around the acceptor peak, has been also detected by means of time-resolved PL. Samples with a higher nitrogen concentration show a PL spectrum t…

Elucidating the electron transport in semiconductors via Monte Carlo simulations: An inquiry-driven learning path for engineering undergraduates

2015

Within the context of higher education for science or engineering undergraduates, we present an inquiry-driven learning path aimed at developing a more meaningful conceptual understanding of the electron dynamics in semiconductors in the presence of applied electric fields. The electron transport in a nondegenerate n-type indium phosphide bulk semiconductor is modelled using a multivalley Monte Carlo approach. The main characteristics of the electron dynamics are explored under different values of the driving electric field, lattice temperature and impurity density. Simulation results are presented by following a question-driven path of exploration, starting from the validation of the model…

Stimulated Emission in InGaN/GaN Multiple Quantum Wells with Different Indium Content

2005

1. IntroductionLight-emitting and laser diodes for the green to near-UV region are basedon quantum structures with the InGaN active region [1]. The indium contentin the wells is a technological parameter that provides a straightforward accessfor the change in the color of the light-emitting device. However, the redshift ofthe emission peak with increase in indium content is caused not only by a simplealloying, but also by carrier localization due to difierence in In and Ga atomic

Chronoamperometry of prussian blue films on ITO electrodes: Ohmic drop and film thickness effect

1999

Abstract The chronoamperograms associated with the reduction of prussian blue films deposited onto indium tin oxide (ITO) electrodes to the Everitt’s salt form, are influenced by the ohmic drop effect. These chronoamperometric curves have been simulated by means of a numerical finite difference model which is able to explain their shape and their dependence on the thickness of the film and on the uncompensated resistance. An analytical expression which describes the dependence of current against time at initial times considering the ohmic drop effect has also been proved when applied to these chronoamperometric curves at short times.

Electrochemical deposition of different semiconductors for application in solar cells

2011

High accuracy Raman measurements using the Stokes and anti-Stokes lines

1997

We show that by measuring the separation between the Stokes and anti-Stokes peaks excited by two different laser lines we obtain a very precise determination of absolute phonon energies. The method is useful for measuring small changes of these energies with strain, temperature, laser power, etc. It doubles the changes and avoids the necessity of using the reference lines in the Raman spectra. The method can be applied for the determination of phonon deformation potentials, for the characterization of strained heteroepitaxial layers, and for micro-Raman analysis of strain in silicon integrated circuits. We give examples of phonon shifts in Si, Ge, GaAs, InAs, and GaP as a function of applie…

Electrical Resistivity Anisotropy of Silicon-Doped n-Indium Selenide

1993

TCO/Ag/TCO transparent electrodes for solar cells application

2014

Among transparent electrodes, transparent conductive oxides (TCO)/metal/TCO structures can achieve optical and electrical performances comparable to, or better than, single TCO layers and very thin metallic films. In this work, we report on thin multilayers based on aluminum zinc oxide (AZO), indium tin oxide (ITO) and Ag deposited by RF magnetron sputtering on soda lime glass at room temperature. The TCO/Ag/TCO structures with thicknesses of about 50/10/50 nm were deposited with all combinations of AZO and ITO as top and bottom layers. While the electrical conductivity is dominated by the Ag intralayer irrespective of the TCO nature, the optical transmissions show a dependence on the natur…