Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

Strassel, Karen; Hu, Wei‐Hsu; Osbild, Sonja; Padula, Daniele; Rentsch, Daniel; Yakunin, Sergii; Shynkarenko, Yevhen; Kovalenko, Maksym V.; Nüesch, Frank; Hany, Roland; Bauer, Michael

doi:10.1080/14686996.2021.1891842

Cited by 17 publications

(28 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed with these donor units, absorption maxima of 882 nm (SQ9) and 935 nm (SQ10) were reached for monomers, which further shifted to 995 nm (SQ10) in the thin film. [199,200] However, because either amorphous layers or only weakly interacting chromophores are present in these materials, no high wavelength selectivity could be achieved which resulted in FWHM EQE values above 200 nm. Although a photoresponse bandwidth of about 100 nm with broadband absorbing and amorphous squaraines (SQ11-13) has been demonstrated using an optical cavity effect, such device structures require a precisely controlled active layer thickness making them again inapplicable for future stacked device architectures (Figure 10).…”

Section: Squaraine Dye Aggregatesmentioning

confidence: 99%

Slip‐Stacked J‐Aggregate Materials for Organic Solar Cells and Photodetectors

et al. 2021

View full text Add to dashboard Cite

Dye–dye interactions affect the optical and electronic properties in organic semiconductor films of light harvesting and detecting optoelectronic applications. This review elaborates how to tailor these properties of organic semiconductors for organic solar cells (OSCs) and organic photodiodes (OPDs). While these devices rely on similar materials, the demands for their optical properties are rather different, the former requiring a broad absorption spectrum spanning from the UV over visible up to the near‐infrared region and the latter an ultra‐narrow absorption spectrum at a specific, targeted wavelength. In order to design organic semiconductors satisfying these demands, fundamental insights on the relationship of optical properties are provided depending on molecular packing arrangement and the resultant electronic coupling thereof. Based on recent advancements in the theoretical understanding of intermolecular interactions between slip‐stacked dyes, distinguishing classical J‐aggregates with predominant long‐range Coulomb coupling from charge transfer (CT)‐mediated or ‐coupled J‐aggregates, whose red‐shifts are primarily governed by short‐range orbital interactions, is suggested. Within this framework, the relationship between aggregate structure and functional properties of representative classes of dye aggregates is analyzed for the most advanced OSCs and wavelength‐selective OPDs, providing important insights into the rational design of thin‐film optoelectronic materials.

show abstract

Section: Squaraine Dye Aggregatesmentioning

confidence: 99%

Slip‐Stacked J‐Aggregate Materials for Organic Solar Cells and Photodetectors

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Small molecules donors based on donor-substituted benz[cd]indole-capped SWIR squaraine dyes (D2-D5) were reported that showed sharp absorption around 1025 nm. These resonance stabilized π-conjugated zwitterionic dyes are comprised of an electron-deficient central four-membered ring and electron-donating groups in a donor-acceptor-donor configuration to achieve narrow bandgaps [208].…”

Section: Organicsmentioning

confidence: 99%

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

Paramasivam

Vella

et al. 2021

Materials Science and Engineering: R: Reports

View full text Add to dashboard Cite

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

show abstract

“…The state‐of‐the‐art of the research on OUCs until 2018 is summarized in ref. [16] Since then, research efforts were directed to extend the detection into the shortwave infrared range, i.e., beyond 1000 nm, [ 11,12,17,18 ] or to improve important device figures of merit, such as lowering the operating voltage or improving the NIR light sensitivity. [ 10,14,15 ]…”

Section: Introductionmentioning

confidence: 99%

On the Response Speed of Narrowband Organic Optical Upconversion Devices

Vael

Diethelm

et al. 2022

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

and are still cost prohibitive for most consumer and low-end applications. In addition, due to the broadband absorption of inorganic semiconductors, spectrally selective detection is not possible without attached optical filters.As an alternative approach, optical upconversion devices have been developed that directly convert NIR light into visible light. These devices are also denoted as upconversion photodetector, [9] upconversion display/imager, [10,11] or upconversion light-emitting diode. [12] The basic idea of any upconverter is the serial connection of a NIR photodetector with a visible lightemitting component. When NIR light is absorbed in the photodetector, a current is generated and directly converted into a visible image by the emitter element. Important advantages of this design concept are that no intermediate electronics for data processing and no external display for data visualization are required. We note that the functionality of an upconverter is different from the several known photon upconversion processes. Photon upconversion is a process that converts sequentially absorbed photons of low energy into a photon of higher energy.All-organic upconversion devices (OUCs) are composed of an organic NIR photodetector and an organic light-emitting diode (OLED). OUCs can be fabricated entirely from solution over large area using coating and printing processes. This potentially enables new and alternative NIR imaging applications Organic upconversion devices (OUCs) consist of an organic infrared photodetector and an organic visible light-emitting diode (OLED), connected in series. OUCs convert photons from the infrared to the visible and are of use in applications such as process control or imaging. Many applications require a fast OUC response speed, namely the ability to accurately detect in the visible a rapidly changing infrared signal. Here, high image-contrast, narrowband OUCs are reported that convert near-infrared (NIR) light at 980 and 976 nm with a full-width at half maximum of 130 nm into visible light. Transient photocurrent measurements show that the response speed decreases when lowering the NIR light intensity. This is contrary to conventional organic photodetectors that show the opposite speed-versus-light trend. It is further found that the response speed increases (when using a phosphorescent OLED) or decreases (for a fluorescent OLED) when increasing the driving voltage. To understand these surprising results, an analysis by numerical simulation is conducted. Results show that the response speed behavior is primarily determined by the electron mobility in the OLED. It is proposed that the low electron drift velocity in the emitter layer sets a fundamental limit to the response speed of OUCs.

show abstract

Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

Abstract: Bauer (2021): Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices, Science and Technology of Advanced Materials,

Cited by 17 publications

References 65 publications

Slip‐Stacked J‐Aggregate Materials for Organic Solar Cells and Photodetectors

Slip‐Stacked J‐Aggregate Materials for Organic Solar Cells and Photodetectors

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

On the Response Speed of Narrowband Organic Optical Upconversion Devices

Contact Info

Product

Resources

About