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An Interface Engineered Multicolor Photodetector Based on n‐Si(111)/TiO 2 Nanorod Array Heterojunction
Author(s) -
Ji Tao,
Liu Qian,
Zou Rujia,
Sun Yangang,
Xu Kaibing,
Sang Liwen,
Liao Meiyong,
Koide Yasuo,
Yu Li,
Hu Junqing
Publication year - 2016
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201504464
Subject(s) - materials science , photodetector , nanorod , heterojunction , optoelectronics , ultraviolet , sputter deposition , etching (microfabrication) , visible spectrum , chemical bath deposition , sputtering , nanotechnology , band gap , thin film , layer (electronics)
A multicolor photodetector based on the heterojunction of n‐Si(111)/TiO 2 nanorod arrays responding to both ultraviolet (UV) and visible light is developed by utilizing interface engineering. The photodetector is fabricated via a consecutive process including chemical etching, magnetron sputtering, hydrothermal growth, and assembling. Under a small reverse bias (from 0 to ≈−2 V), only the photogenerated electrons in TiO 2 are possible to tunnel through the low barrier of Δ E C , and the device only responses to UV light; as the reverse bias increases, the photogenerated holes in Si also begin to tunnel through the high barrier of Δ E V . As a result, the device is demonstrated to have the capacity to detect both UV and visible lights, which is useful in the fields of rapid detection and multicolor imaging. It has been also observed that the crystal orientation of Si affects the characteristics of bias‐controlled spectral response of the n‐Si/TiO 2 heterojunctions.