A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement

In this paper, we studied the optimized conditions for adding inorganic quantum dots (QD) to the P3HT:PC<sub>70</sub>BM organic active layer to increase the sensitivity of the indirect X-ray detector. Commonly used QDs are composed of hazardous substances with environmental problems, so...

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Main Authors: Jehoon Lee, Hailiang Liu, Jungwon Kang
Format: Article
Language:English
Published: MDPI AG 2020-11-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/20/22/6562
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author Jehoon Lee
Hailiang Liu
Jungwon Kang
author_facet Jehoon Lee
Hailiang Liu
Jungwon Kang
author_sort Jehoon Lee
collection DOAJ
description In this paper, we studied the optimized conditions for adding inorganic quantum dots (QD) to the P3HT:PC<sub>70</sub>BM organic active layer to increase the sensitivity of the indirect X-ray detector. Commonly used QDs are composed of hazardous substances with environmental problems, so indium phosphide (InP) QDs were selected as the electron acceptor in this experiment. Among the three different sizes of InP QDs (4, 8, and 12 nm in diameter), the detector with 4 nm InP QDs showed the highest sensitivity, of 2.01 mA/Gy·cm<sup>2</sup>. To further improve the sensitivity, the QDs were fixed to 4 nm in diameter and then the amount of QDs added to the organic active layer was changed from 0 to 5 mg. The highest sensitivity, of 2.26 mA/Gy·cm<sup>2</sup>, was obtained from the detector with a P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) active layer. In addition, the highest mobility, of 1.69 × 10<sup>−5</sup> cm<sup>2</sup>/V·s, was obtained from the same detector. Compared to the detector with the pristine P3HT:PC<sub>70</sub>BM active layer, the detector with a P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) active layer had sensitivity that was 61.87% higher. The cut-off frequency of the P3HT:PC<sub>70</sub>BM detector was 21.54 kHz, and that of the P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) detector was 26.33 kHz, which was improved by 22.24%.
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spelling doaj.art-864c1f2fe6a94631a33e195b82be28222023-11-20T21:13:56ZengMDPI AGSensors1424-82202020-11-012022656210.3390/s20226562A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity ImprovementJehoon Lee0Hailiang Liu1Jungwon Kang2Department of Electronic and Electrical Engineering, Dankook University, Gyeonggi-do 16890, KoreaDepartment of Electronic and Electrical Engineering, Dankook University, Gyeonggi-do 16890, KoreaDepartment of Electronic and Electrical Engineering, Dankook University, Gyeonggi-do 16890, KoreaIn this paper, we studied the optimized conditions for adding inorganic quantum dots (QD) to the P3HT:PC<sub>70</sub>BM organic active layer to increase the sensitivity of the indirect X-ray detector. Commonly used QDs are composed of hazardous substances with environmental problems, so indium phosphide (InP) QDs were selected as the electron acceptor in this experiment. Among the three different sizes of InP QDs (4, 8, and 12 nm in diameter), the detector with 4 nm InP QDs showed the highest sensitivity, of 2.01 mA/Gy·cm<sup>2</sup>. To further improve the sensitivity, the QDs were fixed to 4 nm in diameter and then the amount of QDs added to the organic active layer was changed from 0 to 5 mg. The highest sensitivity, of 2.26 mA/Gy·cm<sup>2</sup>, was obtained from the detector with a P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) active layer. In addition, the highest mobility, of 1.69 × 10<sup>−5</sup> cm<sup>2</sup>/V·s, was obtained from the same detector. Compared to the detector with the pristine P3HT:PC<sub>70</sub>BM active layer, the detector with a P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) active layer had sensitivity that was 61.87% higher. The cut-off frequency of the P3HT:PC<sub>70</sub>BM detector was 21.54 kHz, and that of the P3HT:PC<sub>70</sub>BM:InP QDs (1 mg) detector was 26.33 kHz, which was improved by 22.24%.https://www.mdpi.com/1424-8220/20/22/6562indium phosphide quantum dotphotodetectorindirect X-ray detection
spellingShingle Jehoon Lee
Hailiang Liu
Jungwon Kang
A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
Sensors
indium phosphide quantum dot
photodetector
indirect X-ray detection
title A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
title_full A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
title_fullStr A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
title_full_unstemmed A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
title_short A Study on an Organic Semiconductor-Based Indirect X-ray Detector with Cd-Free QDs for Sensitivity Improvement
title_sort study on an organic semiconductor based indirect x ray detector with cd free qds for sensitivity improvement
topic indium phosphide quantum dot
photodetector
indirect X-ray detection
url https://www.mdpi.com/1424-8220/20/22/6562
work_keys_str_mv AT jehoonlee astudyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement
AT hailiangliu astudyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement
AT jungwonkang astudyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement
AT jehoonlee studyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement
AT hailiangliu studyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement
AT jungwonkang studyonanorganicsemiconductorbasedindirectxraydetectorwithcdfreeqdsforsensitivityimprovement