Evaluation and Properties of a Model for the Determination of Internal Electric Fields in Proteins from the Stark Effect of Spectral Holes

AbstractWe report on a method to investigate the inhomogeneous distribution of an electric dc field in multilayer polymer stacks. In situ electroabsorption (EA) measurements are applied in order to estimate the local electric fields in double layer polymer films. The observed time dependent behaviour is compared with a model equivalent circuit. The results indicate that besides the relation of ohmic resistivities and capacities of the different polymer layers in the investigated systems also the influence of the electric properties of polymer/electrode and polymer/polymer interfaces must be considered.

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Piezoelectric Level Splitting in GaInN/GaN Quantum Wells

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300002726 ◽

1999 ◽

Vol 4 (S1) ◽

pp. 357-362

Author(s):

C. Wetzel ◽

T. Takeuchi ◽

H. Amano ◽

I. Akasaki

Keyword(s):

Quantum Wells ◽

Electric Fields ◽

High Performance ◽

Stark Effect ◽

Electronic Band Structure ◽

Multiple Quantum Well ◽

Multiple Quantum ◽

Large Set ◽

Electronic Band ◽

Level Splitting

Identification of the electronic band structure in AlInGaN heterostructures is the key issue in high performance light emitter and switching devices. In device-typical GaInN/GaN multiple quantum well samples in a large set of variable composition a clear correspondence of transitions in photo- and electroreflection, as well as photoluminescence is found. The effective band offset across the GaN/GaInN/GaN piezoelectric heterointerface is identified and electric fields from 0.23 - 0.90 MV/cm are directly derived. In the bias voltage dependence a level splitting within the well is observed accompanied by the quantum confined Stark effect. We furthermore find direct correspondence of luminescence bands with reflectance features. This indicates the dominating role of piezoelectric fields in the bandstructure of such typical strained layers.

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A III B VI PHOTOVOLTAIC RECEPTORS FOR EXPERIMENTAL DETERMINATION OF CARBON COMPOUNDS IN ATMOSPHERE

Journal of Engineering Studies and Research ◽

10.29081/jesr.v19i3.111 ◽

2016 ◽

Vol 19 (3) ◽

Author(s):

IULIANA CARAMAN ◽

IGOR EVTODIEV ◽

OXANA RACOVEŢ ◽

MARIUS STAMATE

Keyword(s):

Electric Fields ◽

Full Range ◽

Absorption Bands ◽

Gaseous State ◽

Wide Range ◽

Carbon Compounds ◽

Strong Electric Fields ◽

Qualitative Measurements ◽

Semiconductor Type

This paper examines the prospects of using semiconductor layered A III B VI type - photovoltaic cells and the photoresistors as receptors for quantitative and qualitative measurements of carbon oxides. Carbon compounds in gaseous state form absorption bands of electromagnetic radiation in a wide range of spectrum (200 ÷ 100 000) cm-1. The light absorbed or emitted in these bands at the excitations with ionizing radiation (X, γ) or strong electric fields contain direct information about the concentration of these molecules. The frequencies that correspond to maxima of these bands are characteristic parameters of absorbing molecules. Fundamental absorption bands of CO, CO 2 and NC have the edge of band at the border of ultraviolet-vacuum, while the emission bands d cover their full range of wave numbers from 45000 cm-1 to 10000 cm-1. Two types of radiation receptors from lamellar semiconductor type AIIIBVI photosensitive in this spectral range are studied.

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TEMPERATURE DEPENDENCE OF ELECTRICAL RESISTANCE OF INDIVIDUAL CARBON NANOTUBES AND CARBON NANOTUBES NETWORK

Modern Physics Letters B ◽

10.1142/s0217984912501369 ◽

2012 ◽

Vol 26 (21) ◽

pp. 1250136 ◽

Cited By ~ 18

Author(s):

SAJJAD DEHGHANI ◽

MOHAMMAD KAZEM MORAVVEJ-FARSHI ◽

MOHAMMAD HOSSEIN SHEIKHI

Keyword(s):

Carbon Nanotubes ◽

Temperature Dependence ◽

Electric Fields ◽

Electrical Resistance ◽

Electrode Materials ◽

Effect Of Temperature ◽

Electrode Spacing ◽

Single Wall Carbon Nanotubes ◽

Tube Metal

We present a model to understand the effect of temperature on the electrical resistance of individual semiconducting single wall carbon nanotubes (s-SWCNTs) of various diameters under various electric fields. The temperature dependence of the resistance of s-SWCNTs and metallic SWCNTs (m-SWCNTs) are compared. These results help us to understand the temperature dependence of the resistance of SWCNTs network. We experimentally examine the temperature dependence of the resistance of random networks of SWCNTs, prepared by dispersing CNTs in ethanol and drop-casting the solution on prefabricated metallic electrodes. Examining various samples with different electrode materials and spacings, we find that the dominant resistance in determination of the temperature dependence of resistance of the network is the resistance of individual tubes, rather than the tube–tube resistance or tube–metal contact resistance. It is also found that the tube–tube resistance depends on the electrode spacing and it is more important for larger electrode spacings. By applying high electric field to burn the all-metallic paths of the SWCNTs network, the temperature dependence of the resistance of s-SWCNTs is also examined. We also investigate the effect of acid treatment of CNTs on the temperature dependence of the resistance of SWCNTs and also multi-wall CNTs (MWCNTs) networks.

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Determination of the Mobile-Hydrogen Charge State in Hydrogenated Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-664-a28.2 ◽

2001 ◽

Vol 664 ◽

Author(s):

Brent P. Nelsona ◽

Yueqin Xu ◽

Robert C. Reedy ◽

Richard S. Crandall ◽

A. Harv Mahan ◽

...

Keyword(s):

Amorphous Silicon ◽

Electric Fields ◽

Correlation Energy ◽

Hydrogen Charge ◽

Hydrogenated Amorphous Silicon ◽

Mobile Hydrogen ◽

Almost All ◽

Hydrogenated Amorphous ◽

Best Fit

ABSTRACTWe find that hydrogen diffuses as H+, H0, or H- in hydrogenated amorphous silicon depending on its location within the i-layer of a p-i-n device. We annealed a set of five p-i-n devices, each with a thin deuterium-doped layer at a different location in the i-layer, and observed the D-diffusion using secondary ionmass spectrometry (SIMS). When H-diffuses in a charged state, electric fields in the device strongly influence the direction and distance of diffusion. When D is incorporated into a device near the p-layer, almost all of the D-diffusion occurs as D+, and when the D is incorporated near the n-layer, most of the D-diffusion occurs as D-. We correlate the preferential direction of D-motion at given depth within the i-layer, with the local Fermi level (as calculated by solar cell simulations), to empirically determine an effective correlation energy for mobile-H electronic transitions of 0.39 ± 0.1 eV. Using this procedure, the best fit to the data produces a disorder broadening of the transition levels of ∼0.25 eV. The midpoint between the H0/+ and the H0/- transition levels is ∼0.20 ± 0.05 eV above midgap.

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