scholarly journals Descriptors for Electron and Hole Charge Carriers in Metal Oxides

2019 ◽  
Vol 11 (2) ◽  
pp. 438-444 ◽  
Author(s):  
Daniel W. Davies ◽  
Christopher N. Savory ◽  
Jarvist M. Frost ◽  
David O. Scanlon ◽  
Benjamin J. Morgan ◽  
...  
2019 ◽  
Author(s):  
Daniel Davies ◽  
Christopher Savory ◽  
Jarvist Moore Frost ◽  
David Scanlon ◽  
Benjamin Morgan ◽  
...  

<div> <div> <div> <p>Metal oxides can act as insulators, semiconductors or metals depending on their chemical composition and crystal structure. Metal oxide semiconductors, which support equilibrium populations of electron and hole charge carriers, have widespread applications including batteries, solar cells, and display technologies. It is often difficult to predict in advance whether these materials will exhibit localized or delocalized charge carriers upon oxidation or reduction. We combine data from first-principles calculations of the electronic structure and dielectric response of 214 metal oxides to predict the energetic driving force for carrier localization and transport. We assess descriptors based on the carrier effective mass, static polaron binding energy, and Frohlich electron–phonon coupling. Numerical analysis allows us to assign p and n type transport of a metal oxide to three classes: (i) band transport with high mobility; (ii) small polaron transport with low mobility; and (iii) intermediate behaviour. The results of this classification agree with observations regarding carrier dynamics and lifetimes and are used to predict 10 candidate p-type oxides. </p> </div> </div> </div>


2019 ◽  
Author(s):  
Daniel Davies ◽  
Christopher Savory ◽  
Jarvist Moore Frost ◽  
David Scanlon ◽  
Benjamin Morgan ◽  
...  

<div> <div> <div> <p>Metal oxides can act as insulators, semiconductors or metals depending on their chemical composition and crystal structure. Metal oxide semiconductors, which support equilibrium populations of electron and hole charge carriers, have widespread applications including batteries, solar cells, and display technologies. It is often difficult to predict in advance whether these materials will exhibit localized or delocalized charge carriers upon oxidation or reduction. We combine data from first-principles calculations of the electronic structure and dielectric response of 214 metal oxides to predict the energetic driving force for carrier localization and transport. We assess descriptors based on the carrier effective mass, static polaron binding energy, and Frohlich electron–phonon coupling. Numerical analysis allows us to assign p and n type transport of a metal oxide to three classes: (i) band transport with high mobility; (ii) small polaron transport with low mobility; and (iii) intermediate behaviour. The results of this classification agree with observations regarding carrier dynamics and lifetimes and are used to predict 10 candidate p-type oxides. </p> </div> </div> </div>


2012 ◽  
Vol 4 (1) ◽  
pp. 77-80
Author(s):  
Artūras Bubnelis

A new algorithm is utilized to examine the phase and attenuation constants of open dissipative epsilon- and (or) mu-gyrotropic rod waveguides. Our algorithm allows analyzing the waveguides made of materials having very high losses. The dispersion characteristics of p-Ge with a waveguide of two component hole charge carriers are calculated when the ratio of heavy hole concentration in the material is equal to 5%, 50% and 95% of the total free carrier concentration. The effective mass of p-Ge heavy and light holes are 0.279me and 0.043me respectively. The dispersion characteristics of the main and eight higher modes are presented in the paper. The transformation of higher hybrid modes at some heavy hole concentrations can be noticed. Waveguide broad bandwidth can be considerably extended due to the fact that the losses of higher modes are larger in comparison to those of the main mode at certain heavy hole concentration. Santrauka Darbe pateikiami dviejų rūšių krūvininkų (lengvųjų ir sunkiųjų skylučių) puslaidininkinių p-Ge giroelektrinių bangolaidžių, kuriuos veikia B 1 0 = r T indukcijos nuolatinis išilginis magnetinis laukas, dispersinių charakteristikų skaičiavimo rezultatai, įvertinant nuostolius bangolaidyje. Skaičiavimo algoritmas leidžia tirti bangolaidžius, pagamintus iš medžiagų, atnešančių labai didelius nuostolius. Tiriamos 1 mm spindulio bangolaidžių dažninės charakteristikos 5–200 GHz dažnių ruože. Laisvųjų krūvininkų koncentracija bangolaidyje yra N = 5·1019 m–3. Nustatoma nuostolių priklausomybė nuo sunkiųjų skylučių krūvininkų koncentracijos Nh, esant trims skirtingoms sunkiųjų skylučių koncentracijoms, kai Nh sudaro 5 %, 50 % ir 95 % nuo visų krūvininkų koncentracijos N bangolaidyje.


2009 ◽  
Vol 37 (1-4) ◽  
pp. 605-618 ◽  
Author(s):  
Mario Chiesa ◽  
Maria Cristina Paganini ◽  
Elio Giamello
Keyword(s):  

1970 ◽  
Vol 110 (4) ◽  
pp. 53-56 ◽  
Author(s):  
L. Nickelson ◽  
A. Bubnelis ◽  
A. Baskys ◽  
R. Navickas

In this work are examined the phase and attenuation constants of open magnetoactive p-Ge rod waveguides. Our algorithm allows ana-lyzing the very high waveguide losses. Dispersion characteristics of p-Ge with two component hole charge carriers waveguide are calculated when the ratio of heavy holes' concentration in the material is equal to 10%, 30% and 90% of the total free carrier concentration. Dispersion characteristics of the main helicon and eight higher helicon modes are presented here. There are the degeneration and the transformation of higher hybrid modes at some heavy holes' concentrations. The waveguide broadbandwidth can be considerably extended due to the fact that the losses of the higher modes are considerably larger in comparisons to the main mode loss at the certain heavy holes' concentration. Ill. 6, bibl. 12 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.110.4.286


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