Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors
Narrow-bandgap germanium–tin (GeSn) is employed to fabricate metal–semiconductor–metal (MSM) near-infrared photodetectors with low-dark currents and high responsivity. To reduce the dark current, the SiO<sub>2</sub> layer is inserted in between the metal and semiconductor to increase the...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-10-01
|
| Series: | Micromachines |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-666X/13/10/1733 |
| _version_ | 1827648842120560640 |
|---|---|
| author | Ricky Wenkuei Chuang Yu-Hsin Huang Tsung-Han Tsai |
| author_facet | Ricky Wenkuei Chuang Yu-Hsin Huang Tsung-Han Tsai |
| author_sort | Ricky Wenkuei Chuang |
| collection | DOAJ |
| description | Narrow-bandgap germanium–tin (GeSn) is employed to fabricate metal–semiconductor–metal (MSM) near-infrared photodetectors with low-dark currents and high responsivity. To reduce the dark current, the SiO<sub>2</sub> layer is inserted in between the metal and semiconductor to increase the barrier height, albeit at the expense of photocurrent reduction. To couple more incident light into the absorption layer to enhance the responsivity, the distributed Bragg reflectors (DBRs) are deposited at the bottom of the GeSn substrate while placing the anti-reflection layer on the surface of the absorption layer. With the interdigital electrode spacing and width, both set at 5 µm and with 1 V bias applied, it is found the responsivities of the generic MSM control sample detector, the MSM with DBR, and the MSM with AR layer are 0.644 A/W, 0.716 A/W, and 1.30 A/W, respectively. The corresponding specific detectivities are 8.77 × 10<sup>10</sup>, 1.11 × 10<sup>11</sup>, and 1.77 × 10<sup>11</sup> cm·Hz<sup>1/2</sup>/W, respectively. The measurement data show that these designs effectively enhance the photocurrent and responsivity. At 1 V bias voltage, normalized responsivity evinces that the photodetection range has been extended from 1550 nm to over 2000 nm, covering the entire telecommunication band. Incorporating GeSn as a sensing layer offers one of the new alternative avenues for IR photodetection. |
| first_indexed | 2024-03-09T19:46:41Z |
| format | Article |
| id | doaj.art-c2651b8aba35443bab55bfb12a46103f |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T19:46:41Z |
| publishDate | 2022-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-c2651b8aba35443bab55bfb12a46103f2023-11-24T01:23:34ZengMDPI AGMicromachines2072-666X2022-10-011310173310.3390/mi13101733Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared PhotodetectorsRicky Wenkuei Chuang0Yu-Hsin Huang1Tsung-Han Tsai2Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, TaiwanInstitute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, TaiwanInstitute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, TaiwanNarrow-bandgap germanium–tin (GeSn) is employed to fabricate metal–semiconductor–metal (MSM) near-infrared photodetectors with low-dark currents and high responsivity. To reduce the dark current, the SiO<sub>2</sub> layer is inserted in between the metal and semiconductor to increase the barrier height, albeit at the expense of photocurrent reduction. To couple more incident light into the absorption layer to enhance the responsivity, the distributed Bragg reflectors (DBRs) are deposited at the bottom of the GeSn substrate while placing the anti-reflection layer on the surface of the absorption layer. With the interdigital electrode spacing and width, both set at 5 µm and with 1 V bias applied, it is found the responsivities of the generic MSM control sample detector, the MSM with DBR, and the MSM with AR layer are 0.644 A/W, 0.716 A/W, and 1.30 A/W, respectively. The corresponding specific detectivities are 8.77 × 10<sup>10</sup>, 1.11 × 10<sup>11</sup>, and 1.77 × 10<sup>11</sup> cm·Hz<sup>1/2</sup>/W, respectively. The measurement data show that these designs effectively enhance the photocurrent and responsivity. At 1 V bias voltage, normalized responsivity evinces that the photodetection range has been extended from 1550 nm to over 2000 nm, covering the entire telecommunication band. Incorporating GeSn as a sensing layer offers one of the new alternative avenues for IR photodetection.https://www.mdpi.com/2072-666X/13/10/1733metal–semiconductor–metal (MSM) photodetectorsgermanium–tin (GeSn)near-infrareddistributed Bragg reflector (DBR)anti-reflection layer |
| spellingShingle | Ricky Wenkuei Chuang Yu-Hsin Huang Tsung-Han Tsai Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors Micromachines metal–semiconductor–metal (MSM) photodetectors germanium–tin (GeSn) near-infrared distributed Bragg reflector (DBR) anti-reflection layer |
| title | Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors |
| title_full | Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors |
| title_fullStr | Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors |
| title_full_unstemmed | Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors |
| title_short | Germanium-Tin (GeSn) Metal-Semiconductor-Metal (MSM) Near-Infrared Photodetectors |
| title_sort | germanium tin gesn metal semiconductor metal msm near infrared photodetectors |
| topic | metal–semiconductor–metal (MSM) photodetectors germanium–tin (GeSn) near-infrared distributed Bragg reflector (DBR) anti-reflection layer |
| url | https://www.mdpi.com/2072-666X/13/10/1733 |
| work_keys_str_mv | AT rickywenkueichuang germaniumtingesnmetalsemiconductormetalmsmnearinfraredphotodetectors AT yuhsinhuang germaniumtingesnmetalsemiconductormetalmsmnearinfraredphotodetectors AT tsunghantsai germaniumtingesnmetalsemiconductormetalmsmnearinfraredphotodetectors |