scholarly journals Band Offsets at the Interface between Crystalline and Amorphous Silicon from First Principles

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
K. Jarolimek ◽  
E. Hazrati ◽  
R. A. de Groot ◽  
G. A. de Wijs
Keyword(s):  
Amorphous Silicon ◽  
First Principles ◽  
Band Offsets

Electronic band-offsets across Cu2O/BaZrO3 heterojunction and its stable photo-electro-chemical response: First-principles theoretical analysis and experimental optimization

2017 ◽  
Vol 113 ◽  
pp. 503-511 ◽  
Author(s):  
Dipika Sharma ◽  
Rishibrind Kumar Upadhyay ◽  
Biswarup Satpati ◽  
Vibha R. Satsangi ◽  
Rohit Shrivastav ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
First Principles ◽  
Electronic Band ◽  
Band Offsets ◽  
Experimental Optimization ◽  
Chemical Response

scholarly journals Interface Structure and Band Alignment of CZTS/CdS Heterojunction: An Experimental and First-Principles DFT Investigation

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4040 ◽  
Author(s):  
Sachin Rondiya ◽  
Yogesh Jadhav ◽  
Mamta Nasane ◽  
Sandesh Jadkar ◽  
Nelson Y. Dzade
Keyword(s):  
Dft Calculations ◽  
First Principles ◽  
Density Functional ◽  
Rf Sputtering ◽  
Band Alignment ◽  
Charge Carriers ◽  
Band Offsets ◽  
Conduction Band Offset ◽  
Cv Measurements ◽  
Czts Thin Films

We report a phase-pure kesterite Cu2ZnSnS4 (CZTS) thin films, synthesized using radio frequency (RF) sputtering followed by low-temperature H2S annealing and confirmed by XRD, Raman spectroscopy and XPS measurements. Subsequently, the band offsets at the interface of the CZTS/CdS heterojunction were systematically investigated by combining experiments and first-principles density functional theory (DFT) calculations, which provide atomic-level insights into the nature of atomic ordering and stability of the CZTS/CdS interface. A staggered type II band alignment between the valence and conduction bands at the CZTS/CdS interface was determined from Cyclic Voltammetry (CV) measurements and the DFT calculations. The conduction and valence band offsets were estimated at 0.10 and 1.21 eV, respectively, from CV measurements and 0.28 and 1.15 from DFT prediction. Based on the small conduction band offset and the predicted higher positions of the VBmax and CBmin for CZTS than CdS, it is suggested photogenerated charge carriers will be efficient separated across the interface, where electrons will flow from CZTS to the CdS and and vice versa for photo-generated valence holes. Our results help to explain the separation of photo-excited charge carriers across the CZTS/CdS interface and it should open new avenues for developing more efficient CZTS-based solar cells.

Theory of Hydrogen Interactions with Amorphous Silicon

1999 ◽  
Vol 557 ◽  
Author(s):  
Chris G. Van De Walle ◽  
Blair Tuttle
Keyword(s):  
Amorphous Silicon ◽  
First Principles ◽  
Molecular Hydrogen ◽  
Hydrogen Exchange ◽  
Defect Formation ◽  
Exchange Process ◽  
Current Understanding ◽  
First Principles Calculations ◽  
Microscopic Mechanism ◽  
Enhanced Stability

AbstractWe present an overview of recent results for hydrogen interactions with amorphous silicon (a-Si), based on first- principles calculations. We review the current understanding regarding molecular hydrogen, and show that H2 molecules are far less inert than previously assumed. We then discuss results for motion of hydrogen through the material, as relating to diffusion and defect formation. We present a microscopic mechanism for hydrogen-hydrogen exchange, and examine the metastable ≠ SiH2 complex formed during the exchange process. We also discuss the enhanced stability of Si-D compared to Si-H bonds, which may provide a means of suppressing light-induced defect generation.

Effects of Substrate Orientation on the Valence Band Splittings and Valence Band Offsets in GaN and AlN Films

1997 ◽  
Vol 482 ◽  
Author(s):  
J. A. Majewski ◽  
M. Städele
Keyword(s):  
Valence Band ◽  
Conduction Band ◽  
First Principles ◽  
Stacking Fault ◽  
Type I ◽  
Band Offsets ◽  
Substrate Orientation ◽  
First Principles Study

AbstractWe present a first-principles study of heteroepitaxial interfaces between GaN and both cubic as well as wurtzite AlN substrates oriented along main cubic or hexagonal directions and of stacking fault interfaces between cubic and wurtzite GaN. Our calculations show that all studied heterostructures are of type I. Valence band offsets for GaN/AlN are nearly independent of the substrate orientation and of the order of 0.8 eV. The valence and conduction band offsets for a stacking fault interface are predicted to be 40 meV and 175 meV, respectively.

Observation of band structure on amorphous silicon surface and performance of solar cells with controlled band offsets on hetero-junctions

2012 ◽  
Vol 358 (17) ◽  
pp. 2232-2235 ◽  
Author(s):  
Shintaro Miyanishi ◽  
Hideki Koh ◽  
Yoshiro Takaba ◽  
Ryoji Miyamoto ◽  
Atsushi Gorai ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Structure ◽  
Amorphous Silicon ◽  
Silicon Surface ◽  
Band Offsets ◽  
And Performance
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