Determination of hydrogenated amorphous silicon electronic transport parameters and density of states using several photoconductivity techniques

2012 ◽  
Vol 112 (2) ◽  
pp. 023709 ◽  
Author(s):  
C. Longeaud ◽  
F. Ventosinos ◽  
J. A. Schmidt
Keyword(s):  
Amorphous Silicon ◽  
Density Of States ◽  
Electronic Transport ◽  
Hydrogenated Amorphous Silicon ◽  
Transport Parameters ◽  
Hydrogenated Amorphous

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.

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