High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation
PbS films grown on quartz substrates by the chemical bath deposition method were annealed in an O<sub>2</sub> atmosphere to investigate the role of oxygen in the sensitization process at different annealing temperatures. The average grain size of the PbS films gradually increased as the...
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2023-10-01
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author | Quanjiang Lv Rongfan Li Liangchao Fan Zhi Huang Zhenyu Huan Mingyang Yu Haohua Li Guiwu Liu Guanjun Qiao Junlin Liu |
author_facet | Quanjiang Lv Rongfan Li Liangchao Fan Zhi Huang Zhenyu Huan Mingyang Yu Haohua Li Guiwu Liu Guanjun Qiao Junlin Liu |
author_sort | Quanjiang Lv |
collection | DOAJ |
description | PbS films grown on quartz substrates by the chemical bath deposition method were annealed in an O<sub>2</sub> atmosphere to investigate the role of oxygen in the sensitization process at different annealing temperatures. The average grain size of the PbS films gradually increased as the annealing temperature increased from 400 °C to 700 °C. At an annealing temperature of 650 °C, the photoresponsivity and detectivity reached 1.67 A W<sup>−1</sup> and 1.22 × 10<sup>10</sup> cm Hz<sup>1/2</sup> W<sup>−1</sup>, respectively. The role of oxides in the sensitization process was analyzed in combination with X-ray diffraction and scanning electron microscopy results, and a three-dimensional network model of the sensitization mechanism of PbS films was proposed. During the annealing process, O functioned as a p-type impurity, forming p<sup>+</sup>-type PbS layers with high hole concentrations on the surface and between the PbS grains. As annealing proceeds, the p<sup>+</sup>-type PbS layers at the grain boundaries interconnect to form a three-dimensional network structure of hole transport channels, while the unoxidized p-type PbS layers act as electron transport channels. Under bias, photogenerated electron–hole pairs were efficiently separated by the formed p<sup>+</sup>-p charge separation junction, thereby reducing electron–hole recombination and facilitating a higher infrared response. |
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language | English |
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spelling | doaj.art-a835e9048b374d728b41e9839abc37ee2023-11-19T18:02:31ZengMDPI AGSensors1424-82202023-10-012320841310.3390/s23208413High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier SeparationQuanjiang Lv0Rongfan Li1Liangchao Fan2Zhi Huang3Zhenyu Huan4Mingyang Yu5Haohua Li6Guiwu Liu7Guanjun Qiao8Junlin Liu9School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, ChinaPbS films grown on quartz substrates by the chemical bath deposition method were annealed in an O<sub>2</sub> atmosphere to investigate the role of oxygen in the sensitization process at different annealing temperatures. The average grain size of the PbS films gradually increased as the annealing temperature increased from 400 °C to 700 °C. At an annealing temperature of 650 °C, the photoresponsivity and detectivity reached 1.67 A W<sup>−1</sup> and 1.22 × 10<sup>10</sup> cm Hz<sup>1/2</sup> W<sup>−1</sup>, respectively. The role of oxides in the sensitization process was analyzed in combination with X-ray diffraction and scanning electron microscopy results, and a three-dimensional network model of the sensitization mechanism of PbS films was proposed. During the annealing process, O functioned as a p-type impurity, forming p<sup>+</sup>-type PbS layers with high hole concentrations on the surface and between the PbS grains. As annealing proceeds, the p<sup>+</sup>-type PbS layers at the grain boundaries interconnect to form a three-dimensional network structure of hole transport channels, while the unoxidized p-type PbS layers act as electron transport channels. Under bias, photogenerated electron–hole pairs were efficiently separated by the formed p<sup>+</sup>-p charge separation junction, thereby reducing electron–hole recombination and facilitating a higher infrared response.https://www.mdpi.com/1424-8220/23/20/8413lead sulfide filmsinfraredphotodetectorssensitization mechanisms |
spellingShingle | Quanjiang Lv Rongfan Li Liangchao Fan Zhi Huang Zhenyu Huan Mingyang Yu Haohua Li Guiwu Liu Guanjun Qiao Junlin Liu High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation Sensors lead sulfide films infrared photodetectors sensitization mechanisms |
title | High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation |
title_full | High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation |
title_fullStr | High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation |
title_full_unstemmed | High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation |
title_short | High Detectivity of PbS Films Deposited on Quartz Substrates: The Role of Enhanced Photogenerated Carrier Separation |
title_sort | high detectivity of pbs films deposited on quartz substrates the role of enhanced photogenerated carrier separation |
topic | lead sulfide films infrared photodetectors sensitization mechanisms |
url | https://www.mdpi.com/1424-8220/23/20/8413 |
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