Fermi level pinning and band bending in δ-doped BaSnO3

2021 ◽  
Vol 118 (5) ◽  
pp. 052101
Author(s):  
Youjung Kim ◽  
Hyeongmin Cho ◽  
Kookrin Char
1992 ◽  
Vol 259 ◽  
Author(s):  
Chikashi Yamada ◽  
Takahiro Kimura ◽  
Peter Fuqua

ABSTRACTA passivation processes using Na2S and photochemical washing of GaAs (100) surfaces was studied in real time by a second-harmonic generation (SHG) technique. The intensities of surface-specific SHG signals were compared with those of photoluminescence (PL) signals. We found a remarkable similarity between the SHG and PL intensity changes during these processes. A band-bending model due to Fermi-level pinning at the surface has been applied in order to account for both the SHG and the PL intensity changes.


2021 ◽  
Vol 63 (8) ◽  
pp. 991
Author(s):  
О.С. Комков

Photoreflectance is a contactless type of modulation optical spectroscopy. It is used to study the band structure features of monocrystalline semiconductors, their doping level, the composition of alloys, as well as surface and interface band bending. Using high-quality GaAs as an example, the possibilities of describing the photoreflectance lineshape by one-electron and exciton models are demonstrated. The spectra of ultrapure samples of this material exhibit an oscillating structure well described by excitonic effects. For III-V alloys, a review of photoreflectance results concerning the effect of composition and temperature on the band gap and spin-orbit splitting is carried out. Determination of the position of the Fermi level on the surface (Fermi level pinning) for III-V crystals is considered. The currently developing technique for measuring photoreflectance in the mid-infrared range (photomodulation Fourier transform infrared spectroscopy) is described in detail. It is shown that phase correction plays a decisive role in such measurements. Original results demonstrate the capabilities of this method in a wide wavelength range.


1989 ◽  
Vol 54 (6) ◽  
pp. 555-557 ◽  
Author(s):  
E. Yablonovitch ◽  
B. J. Skromme ◽  
R. Bhat ◽  
J. P. Harbison ◽  
T. J. Gmitter

2014 ◽  
Vol 104 (13) ◽  
pp. 132103 ◽  
Author(s):  
Makoto Arita ◽  
Kazuhisa Torigoe ◽  
Takashi Yamauchi ◽  
Takashi Nagaoka ◽  
Toru Aiso ◽  
...  

Carbon ◽  
2013 ◽  
Vol 57 ◽  
pp. 227-231 ◽  
Author(s):  
Hae Kyung Jeong ◽  
Lingmei Hong ◽  
Xin Zhang ◽  
Eduardo Vega ◽  
P.A. Dowben

2018 ◽  
Vol 20 (18) ◽  
pp. 12939-12947 ◽  
Author(s):  
Andrey A. Kistanov ◽  
Yongqing Cai ◽  
Kun Zhou ◽  
Sergey V. Dmitriev ◽  
Yong-Wei Zhang

A proper adoption of the n- or p-type dopants allows for the modulation of the work function, the Fermi level pinning, the band bending, and the photo-adsorbing efficiency near the InSe surface/interface.


2014 ◽  
Vol 1638 ◽  
Author(s):  
Richard Haight ◽  
Aaron Barkhouse ◽  
Wei Wang ◽  
Yu Luo ◽  
Xiaoyan Shao ◽  
...  

ABSTRACTThe heterojunctions formed between solution phase grown Cu2ZnSn(SxSe1- x)4 (CZTS,Se) and a number of important buffer materials including CdS, ZnS, ZnO, and In2S3, were studied using femtosecond ultraviolet photoemission spectroscopy (fs-UPS) and photovoltage spectroscopy. With this approach we extract the magnitude and direction of the CZTS,Se band bending, locate the Fermi level within the band gaps of absorber and buffer and measure the absorber/buffer band offsets under flatband conditions. We will also discuss two-color pump/probe experiments in which the band bending in the buffer layer can be independently determined. Finally, studies of the bare CZTS,Se surface will be discussed including our observation of mid-gap Fermi level pinning and its relation to Voc limitations and bulk defects.


2020 ◽  
Vol 124 (34) ◽  
pp. 18426-18435 ◽  
Author(s):  
Rachel M. Doughty ◽  
Brett Hodges ◽  
Julius Dominguez ◽  
Ruirui Han ◽  
Zeqiong Zhao ◽  
...  

1996 ◽  
Vol 451 ◽  
Author(s):  
O. Henrion ◽  
A. Klein ◽  
C. Ettenkofer ◽  
W. Jaegermann

ABSTRACTTo investigate the initial steps of GaAs etching Br2 and H2O were (co)adsorbed onto the (110) cleavage plane at 100 K and the interaction investigated by SXPS and LEED. H2O is dissociatively adsorbed at low temperatures and leads to Fermi level pinning close to midgap. Br2 leads, depending on coverage, to the formation of bromides of different stoichiometries. During annealing to 290 K the bromides mostly evaporate from the surface (etching). Br2 and H2O coadsorption leads to Ga-oxide remaining on the surface. For the reactive interfaces band bending is not observed. The results of the adsorption experiments are compared to electrochemically prepared surfaces.


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