Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing
This study developed a transparent NO<sub>2</sub> gas sensor with enhanced sensing performance and high optical transmittance. Al-doped ZnO thin films were deposited by atomic layer deposition, which was chosen for its capability to precisely control surface chemistry at the atomic scale...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-06-01
|
| Series: | Sensors |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1424-8220/25/12/3622 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849431425626931200 |
|---|---|
| author | So-Young Bak Se-Hyeong Lee Hyeongrok Jang Minseong Kim Sungjae Kim Moonsuk Yi |
| author_facet | So-Young Bak Se-Hyeong Lee Hyeongrok Jang Minseong Kim Sungjae Kim Moonsuk Yi |
| author_sort | So-Young Bak |
| collection | DOAJ |
| description | This study developed a transparent NO<sub>2</sub> gas sensor with enhanced sensing performance and high optical transmittance. Al-doped ZnO thin films were deposited by atomic layer deposition, which was chosen for its capability to precisely control surface chemistry at the atomic scale. Oxygen vacancies were effectively introduced by utilizing trimethylaluminum, a strongly reducing Al<sub>2</sub>O<sub>3</sub> precursor, thereby increasing carrier concentration and enhancing gas-sensing performance. By adjusting the Al doping level, the optimized device achieved a 50 °C reduction in operating temperature, a 66.2-fold increase in sensitivity at 150 °C, and shortened response and recovery times. The morphology, crystallinity, and elemental distribution were analyzed using transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray spectroscopy, while chemical bonding states were investigated via X-ray photoelectron spectroscopy. Optical properties were characterized using UV–visible spectroscopy, confirming an average transmittance of approximately 80% in the visible range. These results demonstrate the promise of transparent oxide gas sensors for integration into next-generation electronics and Internet of Things-based environmental monitoring systems. |
| format | Article |
| id | doaj-art-39b71fd2893e4d5fa2b648ac4e64225c |
| institution | Kabale University |
| issn | 1424-8220 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj-art-39b71fd2893e4d5fa2b648ac4e64225c2025-08-20T03:27:39ZengMDPI AGSensors1424-82202025-06-012512362210.3390/s25123622Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas SensingSo-Young Bak0Se-Hyeong Lee1Hyeongrok Jang2Minseong Kim3Sungjae Kim4Moonsuk Yi5Department of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaDepartment of Electrical and Electronics Engineering, Pusan National University, Busan 46241, Republic of KoreaThis study developed a transparent NO<sub>2</sub> gas sensor with enhanced sensing performance and high optical transmittance. Al-doped ZnO thin films were deposited by atomic layer deposition, which was chosen for its capability to precisely control surface chemistry at the atomic scale. Oxygen vacancies were effectively introduced by utilizing trimethylaluminum, a strongly reducing Al<sub>2</sub>O<sub>3</sub> precursor, thereby increasing carrier concentration and enhancing gas-sensing performance. By adjusting the Al doping level, the optimized device achieved a 50 °C reduction in operating temperature, a 66.2-fold increase in sensitivity at 150 °C, and shortened response and recovery times. The morphology, crystallinity, and elemental distribution were analyzed using transmission electron microscopy, selected area electron diffraction, and energy-dispersive X-ray spectroscopy, while chemical bonding states were investigated via X-ray photoelectron spectroscopy. Optical properties were characterized using UV–visible spectroscopy, confirming an average transmittance of approximately 80% in the visible range. These results demonstrate the promise of transparent oxide gas sensors for integration into next-generation electronics and Internet of Things-based environmental monitoring systems.https://www.mdpi.com/1424-8220/25/12/3622Al-doped ZnOoxygen vacanciesgas sensorNO<sub>2</sub>Trimethylaluminum |
| spellingShingle | So-Young Bak Se-Hyeong Lee Hyeongrok Jang Minseong Kim Sungjae Kim Moonsuk Yi Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing Sensors Al-doped ZnO oxygen vacancies gas sensor NO<sub>2</sub> Trimethylaluminum |
| title | Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing |
| title_full | Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing |
| title_fullStr | Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing |
| title_full_unstemmed | Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing |
| title_short | Transparent Al-Doped ZnO Thin Films for High-Sensitivity NO<sub>2</sub> Gas Sensing |
| title_sort | transparent al doped zno thin films for high sensitivity no sub 2 sub gas sensing |
| topic | Al-doped ZnO oxygen vacancies gas sensor NO<sub>2</sub> Trimethylaluminum |
| url | https://www.mdpi.com/1424-8220/25/12/3622 |
| work_keys_str_mv | AT soyoungbak transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing AT sehyeonglee transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing AT hyeongrokjang transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing AT minseongkim transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing AT sungjaekim transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing AT moonsukyi transparentaldopedznothinfilmsforhighsensitivitynosub2subgassensing |