Observation of low-dimensional state tunneling in nanocrystalline silicon∕crystalline silicon heterostructures

2004 ◽  
Vol 85 (2) ◽  
pp. 287-289 ◽  
Author(s):  
X. Y. Chen ◽  
W. Z. Shen
Keyword(s):  
Crystalline Silicon ◽  
Nanocrystalline Silicon ◽  
Low Dimensional ◽  
Silicon Heterostructures

Formation of Nanocrystalline Silicon in Tin-Doped Amorphous Silicon Films

2020 ◽  
Vol 65 (3) ◽  
pp. 236
Author(s):  
R. M. Rudenko ◽  
O. O. Voitsihovska ◽  
V. V. Voitovych ◽  
M. M. Kras’ko ◽  
A. G. Kolosyuk ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Crystalline Silicon ◽  
Solid Phase ◽  
Nanocrystalline Silicon ◽  
Recrystallization Temperature ◽  
Nanocrystalline Phase ◽  
Silicon Phase ◽  
Silicon Nanocrystallites ◽  
Lower Temperature ◽  
Two Stages

The process of crystalline silicon phase formation in tin-doped amorphous silicon (a-SiSn) films has been studied. The inclusions of metallic tin are shown to play a key role in the crystallization of researched a-SiSn specimens with Sn contents of 1–10 at% at temperatures of 300–500 ∘C. The crystallization process can conditionally be divided into two stages. At the first stage, the formation of metallic tin inclusions occurs in the bulk of as-precipitated films owing to the diffusion of tin atoms in the amorphous silicon matrix. At the second stage, the formation of the nanocrystalline phase of silicon occurs as a result of the motion of silicon atoms from the amorphous phase to the crystalline one through the formed metallic tin inclusions. The presence of the latter ensures the formation of silicon crystallites at a much lower temperature than the solid-phase recrystallization temperature (about 750 ∘C). A possibility for a relation to exist between the sizes of growing silicon nanocrystallites and metallic tin inclusions favoring the formation of nanocrystallites has been analyzed.

Accelerated interface defect removal in amorphous/crystalline silicon heterostructures using pulsed annealing and microwave heating

2009 ◽  
Vol 95 (18) ◽  
pp. 182108 ◽  
Author(s):  
T. F. Schulze ◽  
H. N. Beushausen ◽  
T. Hansmann ◽  
L. Korte ◽  
B. Rech
Keyword(s):  
Microwave Heating ◽  
Crystalline Silicon ◽  
Interface Defect ◽  
Silicon Heterostructures

p-type nc-SiOx:H emitter layer for silicon heterojunction solar cells grown by rf-PECVD

2015 ◽  
Vol 1770 ◽  
pp. 7-12 ◽  
Author(s):  
Henriette A. Gatz ◽  
Yinghuan Kuang ◽  
Marcel A. Verheijen ◽  
Jatin K. Rath ◽  
Wilhelmus M.M. (Erwin) Kessels ◽  
...  
Keyword(s):  
Solar Cells ◽  
Amorphous Silicon ◽  
Material Properties ◽  
Crystalline Silicon ◽  
Silicon Layer ◽  
Nanocrystalline Silicon ◽  
Emitter Layer ◽  
Heterojunction Solar Cells ◽  
P Type ◽  
Silicon Heterojunction Solar Cells

ABSTRACTSilicon heterojunction solar cells (SHJ) with thin intrinsic layers are well known for their high efficiencies. A promising way to further enhance their excellent characteristics is to enable more light to enter the crystalline silicon (c-Si) absorber of the cell while maintaining a simple cell configuration. Our approach is to replace the amorphous silicon (a-Si:H) emitter layer with a more transparent nanocrystalline silicon oxide (nc-SiOx:H) layer. In this work, we focus on optimizing the p-type nc-SiOx:H material properties, grown by radio frequency plasma enhanced chemical vapor deposition (rf PECVD), on an amorphous silicon layer.20 nm thick nanocrystalline layers were successfully grown on a 5 nm a-Si:H layer. The effect of different ratios of trimethylboron to silane gas flow rates on the material properties were investigated, yielding an optimized material with a conductivity in the lateral direction of 7.9×10-4 S/cm combined with a band gap of E04 = 2.33 eV. Despite its larger thickness as compared to a conventional window a-Si:H p-layer, the novel layer stack of a-Si:H(i)/nc-SiOx:H(p) shows significantly enhanced transmission compared to the stack with a conventional a-Si:H(p) emitter. Altogether, the chosen material exhibits promising characteristics for implementation in SHJ solar cells.

Nanocrystalline Silicon for Optoelectronic Applications

MRS Bulletin ◽  
1998 ◽  
Vol 23 (4) ◽  
pp. 33-38 ◽  
Author(s):  
Leonid Tsybeskov
Keyword(s):  
Binding Energy ◽  
Light Emission ◽  
Crystalline Silicon ◽  
Free Exciton ◽  
Nanocrystalline Silicon ◽  
Momentum Conservation ◽  
Exciton Binding Energy ◽  
Electron Hole ◽  
Energy Plus ◽  
Hole Recombination

Light emission in silicon has been intensively investigated since the 1950s when crystalline silicon (c-Si) was recognized as the dominant material in microelectronics. Silicon is an indirect-bandgap semiconductor and momentum conservation requires phonon assistance in radiative electron-hole recombination (Figure 1a, top left). Because phonons carry a momentum and an energy, the typical signature of phonon-assisted recombination is several peaks in the photoluminescence (PL) spectra at low temperature. These PL peaks are called “phonon replicas.” High-purity c-Si PL is caused by free-exciton self-annihilation with the exciton binding energy of ~11 meV. The TO-phonon contribution in conservation processes is most significant, and the main PL peak (~1.1 eV) is shifted from the bandgap value (~1.17 eV) by ~70 meV—that is, the exciton binding energy plus TO-phonon energy (Figure 1a).

TEM Study and Hall Measurement of nc-Si Prepared by Controlled Deposition

1992 ◽  
Vol 283 ◽  
Author(s):  
Masami Nakata ◽  
Isamu Shimizu
Keyword(s):  
Electrical Transport ◽  
Transport Mechanism ◽  
Crystalline Silicon ◽  
Nanocrystalline Silicon ◽  
Dominant Factor ◽  
Microscopic Structure ◽  
Hall Effect Measurements ◽  
Sample Structure ◽  
Controlled Deposition ◽  
General Transport

ABSTRACTWe report the results of a study in which we combined growth experiments with measurements of the nc-structure and of electrical transport Samples were prepared by plasma enhanced-CVD using SiF4 and H2 gases. We also added PH3 and H2 as control parameters for structural change. The microscopic structure was directly observed by TEM. Electron transport in nc-Si was investigated by Hall effect measurements performed at temperatures from 100K to 400K. We produced samples in which the Hall mobility was applied from general transport mechanism of poly crystalline silicon. However, from TEM observation, we conclude that dominant factor on electrical transport strongly depends on the sample structure, and nanocrystalline-silicon structure is so varied as to make it difficult to determine the transport mechanism without the observation of the microscopic structure.

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