DocumentCode :
30456
Title :
A 
-Si:H Thin-Film Phototransistor for a Near-Infrared Touch Sensor
Author :
Yeonsung Lee ; Omkaram, Inturu ; Park, Jongho ; Hyun-Suk Kim ; Ki-Uk Kyung ; Wook Park ; Sunkook Kim
Author_Institution :
Dept. of Electron. & Radio Eng., Kyung Hee Univ., Yongin, South Korea
Volume :
36
Issue :
1
fYear :
2015
fDate :
Jan. 2015
Firstpage :
41
Lastpage :
43
Abstract :
This letter presents a highly sensitive near-infrared (IR) α-Si:H phototransistor for touch sensor applications. The narrow bandgap of a-Si exhibits a wideband spectrum response from IR to ultraviolet region, where the IR bandpass filter layers allow the α-Si:H phototransistor to respond to the selective IR light uninterrupted by visible light. The time-resolved photoresponse and transfer I-V characteristics for the near-IR α-Si:H phototransistor as a function of power at 785-nm illumination allow the observation of fast photoresponse (τ ~ 0.1 ps), high external quantum efficiency (7.52), and high photoresponse. A prototype unit pixel structure for touch sensors composed of amorphous Si-based switching/amplification/near-IR phototransistors and a storage capacitor, is proposed and designed. The overall results suggest that the near-IR α-Si:H phototransistor offers unique possibilities for user-friendly, low-cost, and large-area touch sensors, especially aimed at consumer applications and other areas of optoelectronics.
Keywords :
amorphous semiconductors; band-pass filters; infrared detectors; narrow band gap semiconductors; phototransistors; silicon; tactile sensors; thin film transistors; IR bandpass filter layer; Si:H; amorphous silicon; external quantum efficiency; narrow bandgap; near-infrared touch sensor; optoelectronics; prototype unit pixel structure; selective IR light; storage capacitor; thin-film phototransistor; time-resolved photoresponse; transfer I-V characteristic; ultraviolet region; visible light; wideband spectrum response; Density measurement; Lighting; Logic gates; Photoconductivity; Phototransistors; Tactile sensors; Thin film transistors; $alpha$ -Si:H; α-Si:H; IR sensor; phototransistor; touch sensor;
fLanguage :
English
Journal_Title :
Electron Device Letters, IEEE
Publisher :
ieee
ISSN :
0741-3106
Type :
jour
DOI :
10.1109/LED.2014.2367118
Filename :
6949127
Link To Document :
