{"title":"Enhancing Dark Current Suppression in Near-Infrared Organic Photodetectors with Morphology Control and Self-Assembled Monolayers","authors":"Wei Fu, Zelong Li, Yifan Ding, Maojie Zhang, Yong Cui, Hong Zhang, Xiaoliang Mo, Rongjun Zhang, Guangzheng Zuo","doi":"10.1002/adom.202500362","DOIUrl":null,"url":null,"abstract":"<p>This study addresses the challenges of high dark current density and low responsivity in near-infrared organic photodetectors (NIR-OPDs) through a synergistic strategy combining morphology control and interface engineering. A thick active layer incorporating solid additives effectively reduces the dark current density while preserving efficient charge transport. Subsequently, molecular interface modification using [2-(9HCarbazol-9-yl)ethyl]phosphonic acid (2PACz) further suppresses the dark current and enhances photoresponsivity. Drift-diffusion modeling, incorporating trap states, reveals that the 2PACz forms a dipole layer at the interface, lowering the injection barrier by ≈0.3 eV and eliminating traps within the device. Together, these strategies reduce the dark current density from the order of 10<sup>−5</sup> A cm<sup>−2</sup> (control) to the order of 10<sup>−8</sup> A cm<sup>−2</sup> at −1 V, and enhance the responsivity (<i>R</i>) from 0.50 A W<sup>−1</sup>(control) to 0.58 A W<sup>−1</sup> at 864 nm. The resulting device exhibits a high shot-noise-limited specific detectivity (<i>D</i><sub>sℎ</sub><sup>∗</sup>) reaching 9.57 × 10<sup>13</sup> Jones, highlighting its exceptional sensitivity. This study demonstrates that combining morphology control with interface engineering effectively overcomes key performance limitations in NIR-OPDs, providing valuable insights for the design of high-performance organic photodetectors.</p>","PeriodicalId":116,"journal":{"name":"Advanced Optical Materials","volume":"13 28","pages":""},"PeriodicalIF":7.2000,"publicationDate":"2025-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Optical Materials","FirstCategoryId":"88","ListUrlMain":"https://advanced.onlinelibrary.wiley.com/doi/10.1002/adom.202500362","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
This study addresses the challenges of high dark current density and low responsivity in near-infrared organic photodetectors (NIR-OPDs) through a synergistic strategy combining morphology control and interface engineering. A thick active layer incorporating solid additives effectively reduces the dark current density while preserving efficient charge transport. Subsequently, molecular interface modification using [2-(9HCarbazol-9-yl)ethyl]phosphonic acid (2PACz) further suppresses the dark current and enhances photoresponsivity. Drift-diffusion modeling, incorporating trap states, reveals that the 2PACz forms a dipole layer at the interface, lowering the injection barrier by ≈0.3 eV and eliminating traps within the device. Together, these strategies reduce the dark current density from the order of 10−5 A cm−2 (control) to the order of 10−8 A cm−2 at −1 V, and enhance the responsivity (R) from 0.50 A W−1(control) to 0.58 A W−1 at 864 nm. The resulting device exhibits a high shot-noise-limited specific detectivity (Dsℎ∗) reaching 9.57 × 1013 Jones, highlighting its exceptional sensitivity. This study demonstrates that combining morphology control with interface engineering effectively overcomes key performance limitations in NIR-OPDs, providing valuable insights for the design of high-performance organic photodetectors.
本研究通过形态学控制和界面工程相结合的协同策略,解决了近红外有机光电探测器(NIR-OPDs)高暗电流密度和低响应率的挑战。含有固体添加剂的厚活性层有效地降低了暗电流密度,同时保持了有效的电荷输运。随后,用[2-(9hcarbazol -9-酰基)乙基]膦酸(2PACz)修饰分子界面,进一步抑制暗电流,提高光响应性。结合陷阱态的漂移扩散模型表明,2PACz在界面处形成偶极子层,使注入势垒降低约0.3 eV,消除了器件内的陷阱。总之,这些策略将暗电流密度从10−5 A cm−2(对照组)降低到10−8 A cm−2(−1 V),并将响应度(R)从0.50 A W−1(对照组)提高到0.58 A W−1(864 nm)。所得到的器件显示出高的脉冲噪声限制比探测率(Ds ),达到9.57 × 1013琼斯,突出了其特殊的灵敏度。该研究表明,将形貌控制与界面工程相结合有效地克服了nir - opd的关键性能限制,为高性能有机光电探测器的设计提供了有价值的见解。
期刊介绍:
Advanced Optical Materials, part of the esteemed Advanced portfolio, is a unique materials science journal concentrating on all facets of light-matter interactions. For over a decade, it has been the preferred optical materials journal for significant discoveries in photonics, plasmonics, metamaterials, and more. The Advanced portfolio from Wiley is a collection of globally respected, high-impact journals that disseminate the best science from established and emerging researchers, aiding them in fulfilling their mission and amplifying the reach of their scientific discoveries.