Tuning the charge blocking layer to enhance photomultiplication in organic shortwave infrared photodetectors

Li, Ning; Lim, Jasmine; Azoulay, Jason D.; Ng, Tse Nga

doi:10.1039/d0tc03013a

Cited by 20 publications

(25 citation statements)

References 42 publications

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“…The visible OLED is forward biased while the SWIR OPD is reverse biased. The OPD is a bulk heterojunction (BHJ) consisting of a SWIR-sensitive polymer [32][33][34][35] and a fullerene derivative [36] whose chemical structures can be found in Figure S1a, Supporting Information. Figure 1e presents the lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) levels of each material.…”

Section: Design Of the Dual-readout Upconversion Imagermentioning

confidence: 99%

Organic Upconversion Imager with Dual Electronic and Optical Readouts for Shortwave Infrared Light Detection

Eedugurala

Leem

et al. 2021

Adv Funct Materials

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There remains a critical need for large‐area imaging technologies that operate in the shortwave infrared spectral region. Upconversion imagers that combine photo‐sensing and display in a compact structure are attractive since they avoid the costly and complex process of pixilation. However, upconversion device research is primarily focused on the optical output, while electronic signals from the imager remain underutilized. Here, an organic upconversion imager that is efficient in both optical and electronic readouts, extending the capability of human and machine vision to 1400 nm, is designed and demonstrated. The imager structure incorporates interfacial layers to suppress non‐radiative recombination and provide enhanced optical upconversion efficiency and electronic detectivity. The photoresponse is comparable to state‐of‐the‐art organic infrared photodiodes exhibiting a high external quantum efficiency of ≤35% at a low bias of ≤3 V and 3 dB bandwidth of 10 kHz. The large active area of 2 cm2 enables demonstrations such as object inspection, imaging through smog, and concurrent recording of blood vessel location and blood flow pulses. These examples showcase the potential of the authors’ dual‐readout imager to directly upconvert infrared light for human visual perception and simultaneously yield electronic signals for automated monitoring applications.

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Section: Design Of the Dual-readout Upconversion Imagermentioning

confidence: 99%

Organic Upconversion Imager with Dual Electronic and Optical Readouts for Shortwave Infrared Light Detection

Eedugurala

Leem

et al. 2021

Adv Funct Materials

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“…To induce photomultiplication, the channel-contact interface are modified to optimize trap sites [19,113] or charge blocking layers [114]. Upon light illumination, the minority charges accumulate and lower the tunneling barrier for majority carrier injection to produce gain.…”

Section: Effect Of Charge Blocking Layers On Photomultiplicative Gainmentioning

confidence: 99%

“…This concept utilizes charge blocking layers to confine carriers at the interface. The two blocking layers allow one type of carrier to recirculate in the device under bias until they recombine with the opposite charge [114]. The dark current is a concern because the charge injection happens at high bias, which reduces the detectivity.…”

Section: Effect Of Charge Blocking Layers On Photomultiplicative Gainmentioning

confidence: 99%

Solution-processable infrared photodetectors: Materials, device physics, and applications

Paramasivam

Vella

et al. 2021

Materials Science and Engineering: R: Reports

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This review is written to introduce infrared photon detectors based on solution-processable semiconductors. A new generation of solution-processable photon detectors have been reported in the past few decades based on colloidal quantum dots, two-dimensional materials, organics semiconductors, and perovskites. These materials offer sensitivity within the infrared spectral regions and the advantages of ease of fabrication at low temperature, tunable materials properties, mechanical flexibility, scalability to large areas, and compatibility with monolithic integration, rendering them as promising alternatives for infrared sensing when compared to vacuum-processed counterparts that require rigorous lattice matching during integration. This work focuses on infrared detection using disordered semiconductors so as to articulate how the inherent device physics and behaviors are different from conventional crystalline semiconductors. The performance of each material family is summarized in tables, and device designs unique to solution-processed materials, including narrowband photodetectors and pixel-less up-conversion imagers, are highlighted in application prototypes distinct from conventional infrared cameras. We share our perspectives in examining open challenges for the development of solution-processable infrared detectors and comment on recent research directions in our community to leverage the advantages of solutionprocessable materials and advance their implementation in next-generation infrared sensing and imaging applications.among many other areas. Commercially available IR detectors are predominantly based on vacuum-processed inorganic compound semiconductors, which are structurally rigid, brittle, and require fabrication via complex epitaxial growth and costly processes. A new generation of solution-processable semiconductors have been reported in the past few decades including colloidal quantum dots (CQDs) [1,8,9], organic semiconductors (OSCs) [4,7,10,11], perovskites [1,12,13], and two-dimensional (2D) materials [5,14]. These materials offer sensitivity within the IR spectral regions and the advantages of ease of fabrication

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“…However, reducing dark current in the PM-type infrared OPDs remains challenging before achieving a high D*. [187] The improvement of infrared OPDs requires effort in advancing materials and device structure. The full understanding of design rules of organic semiconductors with a very small bandgap remains a challenge.…”

Section: Infrared Opdsmentioning

confidence: 99%

Recent Advances in Solution‐Processable Organic Photodetectors and Applications in Flexible Electronics

Lan

Lee

Zhu

2021

Advanced Intelligent Systems

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Organic photodetectors (OPDs) are promising for applications in flexible electronics due to their advantages of excellent photodetection performance, cost-effective solution-fabrication capability, flexible device design, and adaptivity to manufacturability. This review outlines the recent advances in the development of high-performance OPDs and their applications in flexible electronics. The approaches to developing different noise reduction methods, filter-free spectral selective detection, flexible OPDs, and scale-up production of flexible OPDs through solution-fabrication processes are discussed. Applications of the OPD technology ultimately result in the materialization of wearable units, flexible and compact information sensors at commercially viable costs, including wearable health self-monitoring devices, flexible optical communication systems, and flexible large-area image sensors.

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Tuning the charge blocking layer to enhance photomultiplication in organic shortwave infrared photodetectors

Abstract: This work investigates a series of interfacial materials to understand how charge-blocking layers facilitate trap-assisted photomultiplication in organic infrared detectors.

Cited by 20 publications

References 42 publications

Organic Upconversion Imager with Dual Electronic and Optical Readouts for Shortwave Infrared Light Detection

Organic Upconversion Imager with Dual Electronic and Optical Readouts for Shortwave Infrared Light Detection

Solution-processable infrared photodetectors: Materials, device physics, and applications

Recent Advances in Solution‐Processable Organic Photodetectors and Applications in Flexible Electronics

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