{"title":"有机光电探测器中势垒能相关电荷注入机制的理论与实验研究","authors":"Woongsik Jang, Thuc-Quyen Nguyen, Dong Hwan Wang","doi":"10.1002/adfm.202209615","DOIUrl":null,"url":null,"abstract":"<p>Charge injection is known as the major source of dark current under an applied reverse bias, which directly influences the performance of organic photodetectors with diode architecture. However, it is unclear which of various contributions, such as electron flow through the junction, shunt leakage, thermionic emission, and tunnelling, are dominant. This study investigates the thermionic emission and tunneling models to describe the origin of experimentally measured dark current generated in an organic photodetector. To elucidate the dominant mechanism, the barrier energies at anodic contacts are set from 0.6 to 1.0 eV using photosensitive layers composed of different acceptors. A linear relation is found between the natural logarithm of the dark current density under reverse bias and the square root of the barrier height, which strongly suggests direct tunneling as dominant mechanism for dark current injection. This conclusion is strengthened by temperature dependent dark current analysis. Further knowledge of the dominant mechanism by charge injection can help devise an effective strategy to suppress dark current for effective organic photodetector device implementation.</p>","PeriodicalId":112,"journal":{"name":"Advanced Functional Materials","volume":null,"pages":null},"PeriodicalIF":18.5000,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":"{\"title\":\"Theoretical and Experimental Investigation of Barrier-Energy-Dependent Charge Injection Mechanisms in Organic Photodetectors\",\"authors\":\"Woongsik Jang, Thuc-Quyen Nguyen, Dong Hwan Wang\",\"doi\":\"10.1002/adfm.202209615\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>Charge injection is known as the major source of dark current under an applied reverse bias, which directly influences the performance of organic photodetectors with diode architecture. However, it is unclear which of various contributions, such as electron flow through the junction, shunt leakage, thermionic emission, and tunnelling, are dominant. This study investigates the thermionic emission and tunneling models to describe the origin of experimentally measured dark current generated in an organic photodetector. To elucidate the dominant mechanism, the barrier energies at anodic contacts are set from 0.6 to 1.0 eV using photosensitive layers composed of different acceptors. A linear relation is found between the natural logarithm of the dark current density under reverse bias and the square root of the barrier height, which strongly suggests direct tunneling as dominant mechanism for dark current injection. This conclusion is strengthened by temperature dependent dark current analysis. Further knowledge of the dominant mechanism by charge injection can help devise an effective strategy to suppress dark current for effective organic photodetector device implementation.</p>\",\"PeriodicalId\":112,\"journal\":{\"name\":\"Advanced Functional Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":18.5000,\"publicationDate\":\"2022-11-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"4\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advanced Functional Materials\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1002/adfm.202209615\",\"RegionNum\":1,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Functional Materials","FirstCategoryId":"88","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/adfm.202209615","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
Theoretical and Experimental Investigation of Barrier-Energy-Dependent Charge Injection Mechanisms in Organic Photodetectors
Charge injection is known as the major source of dark current under an applied reverse bias, which directly influences the performance of organic photodetectors with diode architecture. However, it is unclear which of various contributions, such as electron flow through the junction, shunt leakage, thermionic emission, and tunnelling, are dominant. This study investigates the thermionic emission and tunneling models to describe the origin of experimentally measured dark current generated in an organic photodetector. To elucidate the dominant mechanism, the barrier energies at anodic contacts are set from 0.6 to 1.0 eV using photosensitive layers composed of different acceptors. A linear relation is found between the natural logarithm of the dark current density under reverse bias and the square root of the barrier height, which strongly suggests direct tunneling as dominant mechanism for dark current injection. This conclusion is strengthened by temperature dependent dark current analysis. Further knowledge of the dominant mechanism by charge injection can help devise an effective strategy to suppress dark current for effective organic photodetector device implementation.
期刊介绍:
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