Light-Response Characteristics of Amorphous Silicon Arrays for Megavoltage and Diagnostic Imaging

1991 ◽  
Vol 219 ◽  
Author(s):  
L. E. Antonuk ◽  
J. Yorkston ◽  
C. W. Kim ◽  
W. Huang ◽  
E. J. Morton ◽  
...  
Keyword(s):  
Diagnostic Imaging ◽  
Amorphous Silicon ◽  
Real Time ◽  
Hydrogenated Amorphous Silicon ◽  
Light Response ◽  
Imaging Arrays ◽  
Response Characteristics ◽  
Fluoroscopic Imaging ◽  
Silicon Arrays ◽  
Hydrogenated Amorphous

ABSTRACTLight-sensitive hydrogenated amorphous silicon pixel arrays are now under development for real-time megavoltage and diagnostic fluoroscopic imaging. Such applications place stringent demands upon a variety of array properties including the uniformity of the light-response function of the pixels. It is desirable that the design and fabrication of these imaging arrays maximize such uniformity. The implications of uniformity for imaging are reviewed, and data obtained from small arrays are presented and discussed.

Real Time Monitoring of the Crystallization of Hydrogenated Amorphous Silicon

2005 ◽  
Vol 862 ◽  
Author(s):  
Paul Stradins ◽  
David Young ◽  
Howard M. Branz ◽  
Matthew Page ◽  
Qi Wang
Keyword(s):  
Amorphous Silicon ◽  
Real Time ◽  
Interference Fringe ◽  
Time Window ◽  
Solid Phase ◽  
Hydrogenated Amorphous Silicon ◽  
Optical Reflectance ◽  
Cutoff Energy ◽  
Hydrogenated Amorphous

AbstractIn-situ real-time optical reflectance spectroscopy is applied to investigate structural changes as hydrogenated amorphous silicon (a-Si:H) loses H and crystallizes at elevated temperature. The interference fringe spectrum (cutoff energy and amplitude) mainly characterize changes in the bulk, while the the crystal Si (c-Si) direct-transition ultra-violet reflectance signatures reveal the presence of any crystalline phase at the surface. Effusion of atomic hydrogen is monitored by a decrease of the interference fringe cutoff energy and is thermally activated with about 1.7 eV. In a-Si:H on glass, optical reflectance spectra are consistent with 2.8 eV activated homogeneous nucleation and growth of a small grain (˜ 100 nm) polycrystalline phase. In contrast, a-Si:H on c-Si crystallizes by solid phase epitaxy with very different spectral kinetics. Our measurements reveal the temperature-time window for thermal crystallization of a-Si:H for photovoltaic device applications, and highlight the versatility of the in-situ spectral reflectance monitoring.

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