scholarly journals Amorphous Silicon-Germanium Films with Embedded Nanocrystals for Thermal Detectors with Very High Sensitivity

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Cesar Calleja ◽  
Alfonso Torres ◽  
Pedro Rosales-Quintero ◽  
Mario Moreno
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
Focal Plane Arrays ◽  
Large Temperature ◽  
Thermal Coefficient ◽  
Thermal Detectors ◽  
Germanium Films ◽  
Amorphous Silicon Germanium ◽  
Very High

We have optimized the deposition conditions of amorphous silicon-germanium films with embedded nanocrystals in a plasma enhanced chemical vapor deposition (PECVD) reactor, working at a standard frequency of 13.56 MHz. The objective was to produce films with very large Temperature Coefficient of Resistance (TCR), which is a signature of the sensitivity in thermal detectors (microbolometers). Morphological, electrical, and optical characterization were performed in the films, and we found optimal conditions for obtaining films with very high values of thermal coefficient of resistance (TCR = 7.9% K−1). Our results show that amorphous silicon-germanium films with embedded nanocrystals can be used as thermosensitive films in high performance infrared focal plane arrays (IRFPAs) used in commercial thermal cameras.

Properties of Catalytic-Cvd Amorphous Silicon-Germanium (a-SiGe:H)

1990 ◽  
Vol 192 ◽  
Author(s):  
Hideki Matsumura ◽  
Masaaki Yamaguchi ◽  
Kazuo Morigaki
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Characteristic Energy ◽  
Optical Band Gaps ◽  
Spin Resonance ◽  
Amorphous Silicon Germanium ◽  
Conductive Properties ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon-germanium (a-SiGe:H) films are prepared by the catalytic chemical vapor deposition (Cat-CVD) method using a SiH4, GeH4 and H4 gas mixture. Properties of the films are investigated by the photo-thermal deflection spectroscopy (PDS) and electron spin resonance (ESR) measurements, in addition to the photo-conductive and structural studies. It is found that the characteristic energy of Urbach tail, ESR spin density and other photo-conductive properties of Cat-CVD a-SiGe:H films with optical band gaps around 1.45 eV are almost equivalent to those of the device quality glow discharge hydrogenated amorphous silicon (a-Si:H).

The Effect of Plasma Power on the Properties of Amorphous Silicon-Germanium Thin Films

2011 ◽  
Vol 317-319 ◽  
pp. 341-344
Author(s):  
Long Gu ◽  
Hui Dong Yang ◽  
Bo Huang
Keyword(s):  
Thin Films ◽  
Amorphous Silicon ◽  
Deposition Rate ◽  
Silicon Germanium ◽  
Structural Characteristics ◽  
Chemical Vapor ◽  
Plasma Power ◽  
Glass Substrates ◽  
Frequency Plasma ◽  
Amorphous Silicon Germanium

Amorphous Silicon-germanium films were prepared by radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) on glass substrates. The structural characteristics, deposition rate, photosensitivity, and optical band gap of the silicon-germanium thin films were investigated with plasma power varying from 15W to 45W. The deposition rate increased within a certain range of plasma power. With the plasma power increasing, the photosensitivity of the thin films decreased. It is evident that varying the plasma power changes the deposition rate, photosensitivity, which was fundamentally crucial for the fabrication of a-Si/a-SiGe/a-SiGe stacked solar cells. For our deposition system, the most optimization value was 30-35W.

Effect of Ge Incorporation on Hydrogenated Amorphous Silicon Germanium Thin Films Prepared by Plasma Enhanced Chemical Vapor Deposition

2012 ◽  
Vol 569 ◽  
pp. 27-30
Author(s):  
Bao Jun Yan ◽  
Lei Zhao ◽  
Ben Ding Zhao ◽  
Jing Wei Chen ◽  
Hong Wei Diao ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous

Hydrogenated amorphous silicon germanium thin films (a-SiGe:H) were prepared via plasma enhanced chemical vapor deposition (PECVD). By adjusting the flow rate of GeH4, a-SiGe:H thin films with narrow bandgap (Eg) were fabricated with high Ge incorporation. It was found that although narrow Eg was obtained, high Ge incorporation resulted in a great reduction of the thin film photosensitivity. This degradation was attributed to the increase of polysilane-(SiH2)n, which indicated a loose and disordered microstructure, in the films by systematically investigating the optical, optoelectronic and microstructure properties of the prepared a-SiGe:H thin films via transmission, photo/dark conductivity, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) measurements. Such investigation provided a helpful guide for further preparing narrow Eg a-SiGe:H materials with good optoelectronic properties.

Amorphous Silicon—Germanium Deposited by Photo—CVD

1985 ◽  
Vol 49 ◽  
Author(s):  
H. Itozaki ◽  
N. Fujita ◽  
H. Hitotsuyanagi
Keyword(s):  
Solar Cell ◽  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Silicon Germanium ◽  
Chemical Vapor ◽  
High Quality ◽  
Transmission Electron ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous ◽  
Gas Ratio

AbstractHydrogenated amorphous silicon germanium (a—SiGe:H) films were deposited by photo—chemical vapor deposition (Photo—CVD) of SiH4 and GeH4 with mercury sensitizer. Their band gap was controlled from 0.9 eV to 1.9 eV by changing the gas ratio of SiH4 and GeH4. High quality opto—electrical properties have been obtained for thea—SiGe:H films by Photo—CVD. Hydrogen termination and microstructure of a-SiGe:H were investigated by infrared absorption and transmission electron microscopy. Ana—Si:H solar cell and an a—Si:H/a—SiGe:H stacked solar cell were made, each of which has conversion efficiency 5.3% and 5.1%, respectively.

Short-range compositional randomness of hydrogenated amorphous silicon–germanium films

2002 ◽  
Vol 92 (2) ◽  
pp. 801-807 ◽  
Author(s):  
B. D. Chapman ◽  
S.-W. Han ◽  
G. T. Seidler ◽  
E. A. Stern ◽  
J. David Cohen ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Silicon Germanium ◽  
Short Range ◽  
Hydrogenated Amorphous Silicon ◽  
Germanium Films ◽  
Amorphous Silicon Germanium ◽  
Hydrogenated Amorphous
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