Characteristics of electron spin resonance in hydrogenated amorphous silicon‐carbon/hydrogenated amorphous silicon heterojunctions

1989 ◽  
Vol 54 (9) ◽  
pp. 807-809 ◽  
Author(s):  
Guanghua Chen ◽  
Guosheng Sun ◽  
Fangqing Zhang
2009 ◽  
Vol 1153 ◽  
Author(s):  
Brian J. Simonds ◽  
Feng Zhu ◽  
Josh Gallon ◽  
Jian Hu ◽  
Arun Madan ◽  
...  

AbstractHydrogenated amorphous silicon carbide alloys are being investigated as a possible top photoelectrode in photoelectrochemical cells used for hydrogen production through water splitting. In order to be used as such, it is important that the effects of carbon concentration on bonding, and thus on the electronic and optical properties, is well understood. Electron spin resonance experiments were performed under varying experimental conditions to study the defect concentrations. The dominant defects are silicon dangling bonds. At room temperature, the spin densities varied between 1016 and 1018 spins/cm3 depending on the carbon concentration. Photothermal deflection spectroscopy, which is an extremely sensitive measurement of low levels of absorption in thin films, was performed to investigate the slope of the Urbach tail. These slopes are 78 meV for films containing the lowest carbon concentration and 98 meV for those containing the highest carbon concentration.


1997 ◽  
Vol 467 ◽  
Author(s):  
Baojie Yan ◽  
P. C. Taylor

ABSTRACTElectron spin resonance (ESR) and light-induced electron spin resonance (LESR) measurements were performed on sulfur-doped hydrogenated amorphous silicon (a-SiS:H). At low S doping levels (H2S/SiH4 ≤ 10−3 in gas phase), the ESR and LESR line shapes are similar to those observed in undoped a-Si:H. The dark spin density generally increases with S doping and reaches 5×1016 cm−3 at H2S/SiH4 ≈ 10−3. On the other hand, at high S concentration, the dark spin density increases significantly with S concentration. The ESR and LESR line shapes become identical and asymmetric, a fact that implies the ESR and LESR signals result from the same kind of ESR center. Since S doping is very inefficient, the ESR signals probably are due to defects instead of trapped carriers in band tails. The asymmetry of the ESR and LESR line shapes at high sulfur concentration may result from either more than one type of defect or an asymmetry in the g tensor of a single defect. The photo-excitation of H-passivated, S-related defects could also contribute to the LESR.


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