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Evaluation of thin‐film photodevices and application to an artificial retina
Author(s) -
Kimura Mutsumi,
Shima Takehiro,
Yamashita Takehiko,
Nishizaki Yoshitaka,
Hara Hiroyuki,
Inoue Satoshi
Publication year - 2008
Publication title -
journal of the society for information display
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.578
H-Index - 52
eISSN - 1938-3657
pISSN - 1071-0922
DOI - 10.1889/1.2938867
Subject(s) - thin film , photodiode , materials science , optoelectronics , illuminance , photodetector , retina , substrate (aquarium) , layer (electronics) , voltage , electric field , optics , computer science , nanotechnology , electrical engineering , physics , oceanography , engineering , quantum mechanics , geology
— First, conventional poly‐Si thin‐film photodevices, p‐i‐n thin‐film photodiodes (TFPDs) and p‐n TFPDs, were evaluated. It was found that the photo‐induced current ( Iphoto ) is not simultaneously relatively high and independent of the applied voltage ( Vapply ). Next, a novel poly‐Si thin‐film photodevice, p‐i‐n thin‐film phototransistor (TFPT), is proposed. It is found that the Iphoto is simultaneously relatively high and independent of the Vapply because the depletion layer is formed in the entire intrinsic region and the electric field is always high. These characteristics are preferable for photosensor applications. Finally, the p‐i‐n TFPT was applied to an artificial retina. The photo‐illuminance profile is correctly detected and the output voltage profile is correspondingly outputted. This artificial retina is expected to be suitable for human beings because it can potentially be fabricated on a flexible, harmless, plastic, and organic substrate.