Potential Profiles in Amorphous Alloys Devices

1989 ◽  
Vol 149 ◽  
Author(s):  
R. Vanderhaghen ◽  
C. Longeaud
Keyword(s):  
Amorphous Silicon ◽  
Spatial Resolution ◽  
Amorphous Alloys ◽  
Hydrogenated Amorphous Silicon ◽  
Time Of Flight ◽  
Internal Field ◽  
Field Profile ◽  
Schottky Structure ◽  
Hydrogenated Amorphous ◽  
Better Than

ABSTRACTThe standard time of flight technique is modified to analyse the internal field profiles in hydrogenated amorphous silicon or amorphous alloys devices. The spatial resolution of the field can be better than a thousand angstroms.With this method the internal field profile in a Schottky structure, built in the sandwich geometry Pt/a-SiGe:H/Cr, was studied. The field profile is found to decrease exponentially with the distance to the Pt/a-SiGe. We also underline the non-ohmic behaviour of the a-SiGe/Cr interface. The shape of the internal field along the intrinsic zone in P-I-N devices is also studied by the same method.The variations of the field profiles in both devices (Schottky and P-IN) with various applied DC biases is presented.

scholarly journals Hole Drift Mobility Measurements on a-Si:H using Surface and Uniformly Absorbed Illumination

2009 ◽  
Vol 1153 ◽  
Author(s):  
Steluta Adriana Dinca ◽  
Eric A Schiff ◽  
Subhendu Guha ◽  
Baojie Yan ◽  
Jeff Yang
Keyword(s):  
Stainless Steel ◽  
Solar Cells ◽  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Time Of Flight ◽  
Drift Mobility ◽  
Electrode Interface ◽  
Steel Substrates ◽  
Hydrogenated Amorphous ◽  
Time Of Flight Method

AbstractThe standard, time-of-flight method for measuring drift mobilities in semiconductors uses strongly absorbed illumination to create a sheet of photocarriers near an electrode interface. This method is problematic for solar cells deposited onto opaque substrates, and in particular cannot be used for hole photocarriers in hydrogenated amorphous silicon (a Si:H) solar cells using stainless steel substrates. In this paper we report on the extension of the time-of-flight method that uses weakly absorbed illumination. We measured hole drift-mobilities on seven a Si:H nip solar cells using strongly and weakly absorbed illumination incident through the n-layer. For thinner devices from two laboratories, the drift-mobilities agreed with each other to within our random error of about 15%. For thicker devices from United Solar, the drift-mobilities were about twice as large when measured using strongly absorbed illumination. We propose that this effect is due to a mobility profile in the intrinsic absorber layer in which the mobility decreases for increasing distance from the substrate.

Electron and Hole Transient Currents in Hydrogenated Amorphous Silicon and Some Alloys Measured by The Photoconductive Time-of-Flight Technique

1998 ◽  
Vol 507 ◽  
Author(s):  
Astrid Eliat ◽  
Guy Adriaenssens ◽  
Baojie Yan
Keyword(s):  
Space Charge ◽  
Amorphous Silicon ◽  
Density Of States ◽  
Hydrogenated Amorphous Silicon ◽  
Time Of Flight ◽  
Relative Increase ◽  
High Light ◽  
Transient Currents ◽  
Fast Decrease ◽  
Hydrogenated Amorphous

ABSTRACTA series of pure hydrogenated amorphous silicon (a-Si:H) samples as well as carbon (aSi:C:H) and sulfur alloys (a-Si:S:H) were investigated by means of the photoconductive time-of-flight technique. Drift moblility (µd) measurements reveal a fast decrease of the electron µd upon C or S addition, while the hole µd does not change significantly. Contrary to the electron transients, hole transient currents do not show the typical space-charge-limited (SCL) features, even for high light intensities where these features are normally seen. SCL features are observed to disappear for electron transients as well in the a-Si:H alloys with increasing alloy content. Above results are all explained starting from the a-Si:H density of states (DOS) model where the valence band (VB) tail is much broader than the conduction band (CB) tail. Introducing additional disorder by alloying broadens both the VB and the CB tails while the relative increase of the CB tail is much greater than that of the VB tail.

Post-transit time-of-flight currents as a probe of the density of states in hydrogenated amorphous silicon

1989 ◽  
Vol 39 (14) ◽  
pp. 10196-10205 ◽  
Author(s):  
G. F. Seynhaeve ◽  
R. P. Barclay ◽  
G. J. Adriaenssens ◽  
J. M. Marshall
Keyword(s):  
Amorphous Silicon ◽  
Density Of States ◽  
Transit Time ◽  
Hydrogenated Amorphous Silicon ◽  
Time Of Flight ◽  
Hydrogenated Amorphous

BONDING IN HYDROGENATED AMORPHOUS SILICON

1981 ◽  
Vol 42 (C4) ◽  
pp. C4-773-C4-777 ◽  
Author(s):  
H. R. Shanks ◽  
F. R. Jeffrey ◽  
M. E. Lowry
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous
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