High-performance near-infrared PtSe2/n-Ge heterojunction photodetector with ultrathin Al2O3 passivation interlayer
Two-dimensional (2D) materials are being intensively exploited for broadband-responsive photodetectors (PDs). However, the broadband-responsive PDs based on 2D materials normally suffer from poor response to infrared wavelengths. Here, we report the excellent photoresponse performance of vertical Pt...
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Published in | Science China materials Vol. 66; no. 7; pp. 2777 - 2787 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Beijing
Science China Press
01.07.2023
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Two-dimensional (2D) materials are being intensively exploited for broadband-responsive photodetectors (PDs). However, the broadband-responsive PDs based on 2D materials normally suffer from poor response to infrared wavelengths. Here, we report the excellent photoresponse performance of vertical PtSe
2
/ultrathin Al
2
O
3
/Ge PD under near-infrared illumination. We directly selenize Pt film deposited on Al
2
O
3
/Ge to form PtSe
2
layer. The ultrathin Al
2
O
3
passivation layer plays the role of surface modification, effectively weakening recombination of the photogenerated carriers. Under 1550-nm illumination, the PtSe
2
/ultrathin Al
2
O
3
/Ge PD with a working area of 50 µm × 50 µm at zero bias obtains a large responsivity of 4.09 A W
−1
, and fast rise/fall times of 32.6/18.9 µs, respectively. And under an external electric field of −5 V, the responsivity and response speed of the PtSe
2
/ultrathin Al
2
O
3
/Ge PD can be as high as 38.18 A W
−1
and as fast as 9.6/7.7 µs, respectively. We find that the working area has a great influence on the photoresponse characteristics. Furthermore, we demonstrate the PtSe
2
/ultrathin Al
2
O
3
/Ge PDs array shows outstanding violet, visible, and infrared imaging capability at room temperature. Our study suggests that the PtSe
2
/ultrathin Al
2
O
3
/Ge heterojunction has great application prospects for the design of emerging broadband optoelectronic devices with superior performance for near-infrared response. |
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ISSN: | 2095-8226 2199-4501 |
DOI: | 10.1007/s40843-022-2402-3 |