Analysis of Non-Uniform Creation of Light-Induced Defects in Schottky Barrier Solar Cell Structures

1995 ◽  
Vol 377 ◽  
Author(s):  
Hongyue Liu ◽  
C. T. Malone ◽  
C. M. Fortmaiiii ◽  
C. R. Wronski
Keyword(s):  
Schottky Barrier ◽  
Electric Fields ◽  
Red Light ◽  
Hydrogenated Amorphous Silicon ◽  
Defect Distribution ◽  
Cell Structures ◽  
Gap States ◽  
Induced Defects ◽  
Hydrogenated Amorphous ◽  
Defect Densities

ABSTRACTHydrogenated amorphous silicon (a-Si:H) TCO/n+/i/Ni Schottky barrier solar cells were degraded with illuminations of white and red light through both sides of the structure. Because the forward dark I-V's are sensitive to the distribution and any spatial variation of defects in the i-layer, these measurements were used to characterize the degraded cell structures. These characteristics were analyzed using a charged defect distribution of gap states consisting of D+, D°, and D states derived from corresponding film analysis. It was found that the non-uniformities of light induced defects created in the i-layer can be represented by two regions of different defect densities. The relative densities depend on the direction of illumination and their ratio even with white light is about a factor of four. This non-uniformity is expected to be less for p-i-n cells which have higher built-in potential and hence electric fields.

Determination of the Mobile-Hydrogen Charge State in Hydrogenated Amorphous Silicon

2001 ◽  
Vol 664 ◽  
Author(s):  
Brent P. Nelsona ◽  
Yueqin Xu ◽  
Robert C. Reedy ◽  
Richard S. Crandall ◽  
A. Harv Mahan ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Electric Fields ◽  
Correlation Energy ◽  
Hydrogen Charge ◽  
Hydrogenated Amorphous Silicon ◽  
Mobile Hydrogen ◽  
Almost All ◽  
Hydrogenated Amorphous ◽  
Best Fit

ABSTRACTWe find that hydrogen diffuses as H+, H0, or H- in hydrogenated amorphous silicon depending on its location within the i-layer of a p-i-n device. We annealed a set of five p-i-n devices, each with a thin deuterium-doped layer at a different location in the i-layer, and observed the D-diffusion using secondary ionmass spectrometry (SIMS). When H-diffuses in a charged state, electric fields in the device strongly influence the direction and distance of diffusion. When D is incorporated into a device near the p-layer, almost all of the D-diffusion occurs as D+, and when the D is incorporated near the n-layer, most of the D-diffusion occurs as D-. We correlate the preferential direction of D-motion at given depth within the i-layer, with the local Fermi level (as calculated by solar cell simulations), to empirically determine an effective correlation energy for mobile-H electronic transitions of 0.39 ± 0.1 eV. Using this procedure, the best fit to the data produces a disorder broadening of the transition levels of ∼0.25 eV. The midpoint between the H0/+ and the H0/- transition levels is ∼0.20 ± 0.05 eV above midgap.

Probing the Densities of Gap States in Intrinsic a-Si:H Using Space Charge Limited Currents of Electrons and Holes

1990 ◽  
Vol 192 ◽  
Author(s):  
Robin M. Dawson ◽  
J. H. Smith ◽  
C. R. Wronski
Keyword(s):  
Space Charge ◽  
Density Of States ◽  
Carrier Transport ◽  
Hydrogenated Amorphous Silicon ◽  
Wide Range ◽  
Self Consistent ◽  
Gap States ◽  
Hydrogenated Amorphous ◽  
Space Charge Limited Currents ◽  
Space Charge Limited

ABSTRACTSpace charge limited currents of holes in intrinsic hydrogenated amorphous silicon (a-Si:H) have been obtained using novel p+-intrinsic-p+ (p-i-p) structures. The presence of these hole space charge limited currents is verified from their temperature dependence and their dependence on a wide range of intrinsic layer thickness. The carrier transport and space charge limited currents in the p-i-p structures are compared with those of n-i-n structures and the results are discussed in terms of a self consistent density of states in the gap.

Hall-Effect and Sign Properties in Hydrogenated Amorphous and Disordered Crystalline Silicon

1996 ◽  
Vol 420 ◽  
Author(s):  
C. E. Nebel ◽  
M. Rother ◽  
C. Summonte ◽  
M. Heintze ◽  
M. Stutzmann
Keyword(s):  
Hall Effect ◽  
Amorphous Silicon ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Small Volume Fraction ◽  
Phosphorus Doped ◽  
Hydrogenated Amorphous ◽  
Defect Densities ◽  
Very High

AbstractHall experiments on a series of microcrystalline, microcrystalline-amorphous, amorphous and crystalline silicon samples with varying defect densities are presented and discussed. Normal Hall effect signatures on boron and phosphorus doped hydrogenated amorphous silicon are detected. We interpret these results to be due to a small volume fraction of nanocrystalline Si, which falls below the detection limits of Raman experiments. Hydrogenated amorphous silicon, prepared under conditions far away from microcrystalline growth, shows the known double sign anomaly, Sign reversals in c-Si, where the disorder is increased by Si implantation up to very high levels, could not be detected.

Hydrogenated amorphous silicon nanowire transistors with Schottky barrier source/drain junctions

2010 ◽  
Vol 97 (14) ◽  
pp. 143509 ◽  
Author(s):  
Kurtis D. Cantley ◽  
Anand Subramaniam ◽  
Ramapriyan R. Pratiwadi ◽  
Herman Carlo Floresca ◽  
Jinguo Wang ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Schottky Barrier ◽  
Silicon Nanowire ◽  
Hydrogenated Amorphous Silicon ◽  
Nanowire Transistors ◽  
Hydrogenated Amorphous
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