Study of insulating electrical conductivity in hydrogenated amorphous silicon–nickel alloys at very low temperature

2011 ◽  
Vol 406 (21) ◽  
pp. 4155-4158 ◽  
Author(s):  
A. Narjis ◽  
A. El kaaouachi ◽  
L. Limouny ◽  
S. Dlimi ◽  
A. Sybous ◽  
...  
1989 ◽  
Vol 149 ◽  
Author(s):  
Byung-Seong Bae ◽  
Deok-Ho Cho ◽  
Jae-Hee Lee ◽  
Choochon Lee ◽  
Jin Jang

ABSTRACTWe investigated the temperature dependent characteristics of hydrogenated amorphous silicon (a-Si:H) thin film transistors (TFT's) at temperatures down to 20 K. With decreasing temperature, the threshold voltage increased, the field effect mobility and the on-current decreased. The measured on-currents versus inverse temperature above 80 K are represented as the sum of two exponentially varied currents. It is concluded that on-current is nearest-neighbour hopping between 120 K and 80 K. Below this temperature, the temperature dependence of on-current is explained by variable range hopping and below about 30 K on-current becomes nearly independent of temperature. At very low temperature hopping probability may be governed not by temperature but by temperature independent tunneling, depending on the overlap of the wave function. The explanation of threshold voltage increase at low temperature is given.


2007 ◽  
Vol 989 ◽  
Author(s):  
Kyung Ho Kim ◽  
Yuriy Vygranenko ◽  
Mark Bedzyk ◽  
Jeff Hsin Chang ◽  
Tsu Chiang Chuang ◽  
...  

AbstractWe report on the fabrication and characterization of hydrogenated amorphous silicon (a-Si:H) films and n-i-p photodiodes on glass and PEN plastic substrates using low-temperature (150°C) plasma-enhanced chemical vapor deposition. Process conditions were optimized for the i-a-Si:H material which had a band gap of ~1.73 eV and low density of states (of the order 1015 cm-3). Diodes with 0.5 μm i-layer demonstrate quantum efficiency ~70%. The reverse dark current of the diodes on glass and PEN plastic substrate is ~10-11 and below 10-10 A/cm2, respectively. We discuss the difference in electrical characteristics of n-i-p diodes on glass and PEN in terms of bulk- and interface-state generation currents.


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