Dangling bond in amorphous hydrogenated silicon: Anomalous spin relaxation

ABSTRACTThe mechanisms of the Staebler-Wronski effect are investigated by examining the stability of computer-generated amorphous hydrogenated silicon networks with a molecular dynamics approach. Models with both monohydride and dihydride species are examined. A new Si-H interatomic potential is utilized for the simulations. A localized excitation is used to model the non-radiative transfer of photo-excited carrier energy to the lattice. The a-Si:H model with only monohydride species is stable to bond-breaking excitations. The a-Si:H model with both monohydride and dihydride species is less stable and exhibits, after local excitations, higher energy dangling bond states that can however be easily annealed away.

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The Dangling Bond in Undoped Amorphous Hydrogenated Silicon: Trap or Recombination Center?

MRS Proceedings ◽

10.1557/proc-70-125 ◽

1986 ◽

Vol 70 ◽

Cited By ~ 3

Author(s):

M. A. Parker ◽

K. A. Conrad ◽

E. A. Schiff

Keyword(s):

Experimental Data ◽

Response Time ◽

Electrical Contacts ◽

Electron Trap ◽

Recombination Center ◽

Photocurrent Response ◽

Dangling Bond ◽

Hydrogenated Silicon ◽

Amorphous Hydrogenated Silicon

ABSTRACTThe role of the neutral dangling bond defect upon photocarrier processes in undoped amorphous hydrogenated silicon (a-Si:H) is discussed. The evidence that the dangling bond is a simple recombination center is reviewed, and it is shown that this model does not account for photocurrent response time measurements. Experimental data pertinent to the role of electrical contacts upon response time measurements are presented, and it is concluded that contact effects do not account for response-time measurements. The possibility that the dangling bond is primarily an electron trap is discussed.

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Microstructure and Dangling Bond Defects in Amorphous Hydrogenated Silicon Deposited Near Room Temperature

MRS Proceedings ◽

10.1557/proc-258-191 ◽

1992 ◽

Vol 258 ◽

Cited By ~ 1

Author(s):

Man Ken Cheung ◽

Mark A. Petrich

Keyword(s):

Room Temperature ◽

Dangling Bond ◽

Optimum Conditions ◽

Band Tail ◽

Hydrogenated Silicon ◽

Photothermal Deflection Spectroscopy ◽

Amorphous Hydrogenated Silicon ◽

Photothermal Deflection ◽

Substrate Temperatures ◽

Absorption Measurements

ABSTRACTThe microstructure of high-density amorphous hydrogenated silicon (a-S.i:H) films deposited at 50°C substrate temperature was revealed by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies to be similar to that of “device-quality” a-Si:H films deposited at standard “optimum” conditions. However, optical absorption measurements of these low microstructure 50°C films with photothermal deflection spectroscopy indicate that they have higher densities of gap state defects and localized band tail states than “device-quality” films deposited at standard substrate temperatures. The correlation between the amount of microstructure and electronic properties is not unique. A low amount of microstructure is a necessary, but not sufficient, requirement for high electronic quality a-Si:H films.

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Optically Induced Paramagnetism in Amorphous Hydrogenated Silicon Nitride Thin Films

MRS Proceedings ◽

10.1557/proc-242-687 ◽

1992 ◽

Vol 242 ◽

Cited By ~ 5

Author(s):

W. L. Warren ◽

J. Kanicki ◽

F. C. Rong ◽

W. R. Buchwald ◽

M. Harmatz

Keyword(s):

Thin Films ◽

Silicon Nitride ◽

Ultra Violet ◽

Dangling Bond ◽

Hydrogenated Silicon ◽

Uv Illumination ◽

Defect Centers ◽

Amorphous Hydrogenated Silicon ◽

The Creation ◽

A Charge

ABSTRACTThe creation mechanisms of Si and N dangling bond defect centers in amorphous hydrogenated silicon nitride thin films by ultra-violet (UV) illumination are investigated. The creation efficiency and density of Si centers in the N-rich films are independent of illumination temperature, strongly suggesting that the creation mechanism of the spins is electronic in nature, i.e., a charge transfer mechanism. However, our results suggest that the creation of the Si dangling bond in the Si-rich films are different. Last, we find that the creation of the N dangling-bond in N-rich films can be fit to a stretched exponential time dependence, which is characteristic of dispersive charge transport.

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Electrically neutral nitrogen dangling‐bond defects in amorphous hydrogenated silicon nitride thin films

Journal of Applied Physics ◽

10.1063/1.349433 ◽

1991 ◽

Vol 70 (4) ◽

pp. 2220-2225 ◽

Cited By ~ 47

Author(s):

W. L. Warren ◽

P. M. Lenahan ◽

J. Kanicki

Keyword(s):

Thin Films ◽

Silicon Nitride ◽

Dangling Bond ◽

Hydrogenated Silicon ◽

Amorphous Hydrogenated Silicon

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Paramagnetic Nitrogen Defects in Silicon Nitride

MRS Proceedings ◽

10.1557/proc-284-101 ◽

1992 ◽

Vol 284 ◽

Cited By ~ 3

Author(s):

W. L. Warren ◽

J. Kanicki ◽

J. Robertson ◽

E. H. Poindexte

Keyword(s):

Silicon Nitride ◽

Energy Level ◽

Theoretical Calculations ◽

Dangling Bond ◽

Compositional Dependence ◽

Hydrogenated Silicon ◽

Amorphous Hydrogenated Silicon ◽

Bond Center ◽

Simple Exponential Function ◽

Post Deposition

ABSTRACTThe photocreation mechanisms and properties of nitrogen dangling bonds in amorphous hydrogenated silicon nitride (a-SiNx:H) thin films are investigated. We find that the creation kinetics are strongly dependent on the post-deposition anneal; this thermal process can be described by a simple exponential function which yields an activation energy of 0.8 eV. The compositional dependence of the nitrogen dangling bond center suggests that its energy level lies close to the valence band edge, in agreement with theoretical calculations. This energy level position can explain why a-SiNx:H films often become conducting following a high post-deposition anneal.

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