scholarly journals Conduction-band edge and Shubnikov–de Haas effect in low-electron-density SrTiO3

2013 ◽  
Vol 88 (4) ◽  
Author(s):  
S. James Allen ◽  
Bharat Jalan ◽  
SungBin Lee ◽  
Daniel G. Ouellette ◽  
Guru Khalsa ◽  
...  
Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 822
Author(s):  
Hyo-Jun Joo ◽  
Dae-Hwan Kim ◽  
Hyun-Seok Cha ◽  
Sang-Hun Song

We measured and analyzed the Hall offset voltages in InGaZnO thin-film transistors. The Hall offset voltages were found to decrease monotonously as the electron densities increased. We attributed the magnitude of the offset voltage to the misalignment in the longitudinal distance between the probing points and the electron density to Fermi energy of the two-dimensional electron system, which was verified by the coincidence of the Hall voltage with the perpendicular magnetic field in the tilted magnetic field. From these results, we deduced the combined conduction band edge energy profiles from the Hall offset voltages with the electron density variations for three samples with different threshold voltages. The extracted combined conduction band edge varied by a few tens of meV over a longitudinal distance of a few tenths of µm. This result is in good agreement with the value obtained from the analysis of percolation conduction.


2014 ◽  
Vol 778-780 ◽  
pp. 424-427
Author(s):  
Tetsuo Hatakeyama ◽  
Mitsuru Sometani ◽  
Kenji Fukuda ◽  
Hajime Okumura ◽  
Tsunenobu Kimoto

Constant-capacitance deep-level transient spectroscopy was carried out to characterize in detail interface states close to the conduction band edge in SiO2/SiC structures. The measured results are summarized as follows: (1) The capture of electrons by the interface states proceeds logarithmically with time. (2) The emission of electrons accelerates slightly with increasing density of captured electrons. The oxide trap model explains the logarithmic change in capture with time but not the phenomenon of accelerated emissions. This prompted us to formulate a new model that replicates the logarithmic capture process with time. In this model, we postulated the electron density at the interface decreases exponentially as the trapped electron density increases owing to the interaction between the trapped electrons and the free electrons. In this case, the capture process is almost the same as with the oxide trap model except for the definition of parameters. Further, we do not need to take into account the delay of the emission process caused by tunneling. The phenomenon of accelerated emissions may be explained by interactions among captured electrons in this model.


ACS Nano ◽  
2011 ◽  
Vol 5 (7) ◽  
pp. 5888-5902 ◽  
Author(s):  
Jacek Jasieniak ◽  
Marco Califano ◽  
Scott E. Watkins

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Gongqin Xu ◽  
Anne de Visser ◽  
Yingkai Huang ◽  
Xingyu Mao

Bi1-xSbx alloys are of special significance in topological insulator research. Here we focus on the Bi0.96Sb0.04 alloy in which the conduction band edge just touches the valence band edge. Transport measurements show quantum oscillations in the longitudinal (Shubnikov–de Haas effect) and transverse magnetoresistance originating from a spheroidal Fermi surface pocket. Further investigation of the longitudinal magnetoresistance for the magnetic field parallel to the electrical current shows a small nonmonotonic magnetoresistance that is attributed to a competition of weak-antilocalization effects and a topological term related to the chiral anomaly.


RSC Advances ◽  
2019 ◽  
Vol 9 (20) ◽  
pp. 11377-11384 ◽  
Author(s):  
Kaili Wei ◽  
Baolai Wang ◽  
Jiamin Hu ◽  
Fuming Chen ◽  
Qing Hao ◽  
...  

It's highly desired to design an effective Z-scheme photocatalyst with excellent charge transfer and separation, a more negative conduction band edge (ECB) than O2/·O2− (−0.33 eV) and a more positive valence band edge (EVB) than ·OH/OH− (+2.27 eV).


2005 ◽  
Vol 483-485 ◽  
pp. 559-562 ◽  
Author(s):  
Kun Yuan Gao ◽  
Thomas Seyller ◽  
Konstantin V. Emtsev ◽  
Lothar Ley ◽  
Florin Ciobanu ◽  
...  

Atomic Layer Deposited Al2O3 films on hydrogen-terminated 6H-SiC(0001) were annealed in hydrogen atmosphere and characterized by admittance spectroscopy measurement and photoelectron spectroscopy (PES). The resultant density of interface trap (Dit) from admittance spectroscopy measurement is reduced near mid gap, but increases strongly towards the conduction band edge. Systematic PES measurements show that hydrogen annealing introduces Si4+ as a new component besides Si0 and Si+. Using different electron escape depths for photon electrons, depth profiling of Si in its different oxidation states was performed. The result indicates the formation of a top SiO2 layer and a rougher interfacial layer containing more Si+ and Si4+ which could be responsible for the strong increase of Dit just below the conduction band edge.


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