Title :
How to achieve ultra high photoconductive gain for transparent oxide semiconductor image sensors
Author :
Sungsik Lee ; Sanghun Jeon ; Robertson, John ; Nathan, Arokia
Author_Institution :
London Center for Nanotechnol., Univ. Coll. London, London, UK
Abstract :
We present quantitative analysis of the ultra-high photoconductivity in amorphous oxide semiconductor (AOS) thin film transistors (TFTs), taking into account the sub-gap optical absorption in oxygen deficiency defects. We analyze the basis of photoconductivity in AOSs, explained in terms of the extended electron lifetime due to retarded recombination as a result of hole localization. Also, photoconductive gain in AOS photo-TFTs can be maximized by reducing the transit time associated with short channel lengths, making device scaling favourable for high sensitivity operation.
Keywords :
amorphous semiconductors; carrier lifetime; image sensors; light absorption; photoconductivity; photodetectors; thin film transistors; AOS; TFT; amorphous oxide semiconductor; electron lifetime; hole localization; optical absorption; oxygen deficiency defect; photoconductive gain; photoconductivity; retarded recombination; thin film transistors; transparent oxide semiconductor image sensor; Absorption; Charge carrier processes; Density measurement; Logic gates; Spontaneous emission; Thin film transistors; Threshold voltage;
Conference_Titel :
Electron Devices Meeting (IEDM), 2012 IEEE International
Conference_Location :
San Francisco, CA
Print_ISBN :
978-1-4673-4872-0
Electronic_ISBN :
0163-1918
DOI :
10.1109/IEDM.2012.6479094
