Research is an energy- and resource-demanding activity. However, despite emerging sustainability initiatives, a paucity of data and uptake of green initiatives continue to hamper effective and accountable emissions mitigation. Worldwide, >250,000 doctoral students graduate annually across all academic disciplines. Empowering students to engage in carbon accounting can raise awareness of sustainability in research and provide a substantial and robust resource of carbon data alongside a powerful community-driven impetus for decarbonization. Here, we demonstrate how students and other researchers can consistently measure the carbon footprint of their work, using 1 PhD student's research in a Drosophila neuroscience lab as our case study. We present a life cycle assessment of the equivalent carbon dioxide emissions generated by the student's research activities. Moreover, we explain how students can create a "carbon appendix' to their research, as a common framework for disseminating carbon data and revealed strategies for improving research sustainability. We argue that the process of creating a carbon appendix can empower researchers to scrutinize sustainability practices, empower them to implement effective green initiatives, and identify data-driven solutions to meet and exceed funders' sustainability targets.

Vertical‐cavity surface‐emitting lasers (VCSELs) are vital for modern photonics, offering compactness, low thresholds, and ease of integration. Pushing them to wavelength‐scale dimensions, however, introduces fabrication and performance challenges, especially when using organic materials. Here, we demonstrate the miniaturization of organic polariton VCSELs based on the blue emitter molecule BSBCz. Using emitter:host evaporation through ultra‐thin shadow masks, we fabricate isolated microcavities with sizes down to 5 µm, the smallest dimensions reported so far for coevaporation micropatterning, and achieved optically‐pumped polariton lasing with record‐low thresholds down to 2.63 pJ (0.21 µJ/cm2), substantially lower than the 21.2 pJ (6.75 µJ/cm2) obtained for unpatterned reference devices. We further elucidate the influence of concentration of active material. Our lateral confinement approach paves the way for scalable, low‐threshold polariton lasers and may support the future development of monolithically integrated organic lasers driven by direct current injection.

We present a graphene photodetector coupled to a layer of aggregated organic semiconductor. A graphene phototransistor is covered with a thin film of merocyanine molecules. The aggregation of the molecular layer can be controlled by the deposition parameters and post-deposition annealing to obtain films ranging from amorphous to a highly aggregated state. The molecular layer has a uniaxial structure with excitonic transitions whose transition dipole moments are well defined. The presence of the molecular layer results in an enormous increase in the response of the phototransistor. We further demonstrate that the signal-enhancement is due to p-photodoping of the graphene. The spectroscopic photoresponse suggests that the photodoping via monomers and molecular aggregates takes place differently. Our photodetector is a platform to study the influence of molecular aggregation and order on charge transport processes between aggregated organic semiconductors and two-dimensional materials.

Thermally activated delayed fluorescence (TADF) emitters enable efficient harvesting of triplet excitons in organic light-emitting diodes (OLEDs), yet their performance is often limited by long-lived triplet populations that promote bimolecular annihilation and efficiency roll-off at high brightness. Here, we introduce a exciton management (EM) that targets triplet accumulation independently of conventional Δ E ST minimization by mixing two TADF emitters with complementary, i.e., fast and slow reverse intersystem crossing (rISC) dynamics. Blending enables composition-dependent modification of the exciton dynamics within a coupled excited-state manifold. Time-resolved spectroscopy reveals that the mixed systems exhibit accelerated delayed fluorescence and enhanced effective rISC rates relative to the pure emitters, while simultaneously maintaining high photoluminescence efficiency. Optical excitation power-dependent measurements demonstrate suppressed annihilation signatures, consistent with reduced steady-state triplet densities under high excitation conditions. OLED devices based on mixed-emitter layers establish an intermediate operating regime, combining high low-luminance external quantum efficiencies of up to 30.8% with retained efficiencies of approximately 10-11% at 1000 cd m -2 . These results establish control over the exciton dynamics as a valuable design principle for TADF systems, providing an alternative to conventional strategies based solely on minimizing singlet-triplet energy gaps. More broadly, the approach offers a general framework for exciton management in multi-emitter OLED architectures and highlights the importance of excited-state kinetics for achieving efficient organic optoelectronic devices under high-brightness operation.

Whispering gallery mode (WGM) microlasers combine high Q factors with remote spectral readout and sensitivity to their microenvironment through refractive index changes. This intrinsic responsiveness, together with the ability of various cell types to internalize such microlasers, has enabled unique opportunities in advanced biological studies, including single cell tracking and intracellular sensing. However, precise delivery of microlasers to cells remains challenging, as conventional approaches such as microinjection often induce cellular stress or damage. In this study, we demonstrate optical trapping as a placement tool to steer individual microlasers onto non-phagocytic mammalian cells and, critically, to uniquely monitor the entire uptake process from plasma-membrane contact to internalization. Real-time spectral signatures, supported by complementary imaging, reveal distinct interaction stages through characteristic shifts, broadening, and mode splitting. By positioning microlasers directly at defined membrane sites, this method also ensures consistent particle-cell encounters, resulting in markedly more reliable uptake events than stochastic approaches. This approach enables single-cell, single-microlaser measurements that reveal heterogeneity in membrane remodeling and uptake behavior, even across a modest number of cells. These capabilities expand the utility of biointegrated microlasers and provide a foundation for mechanistic studies of membrane dynamics, uptake pathways, and intracellular sensing, while supporting comparisons of surface coatings and cell-type responses.

The fabrication of organic light-emitting diodes (OLEDs) typically proceeds via vacuum deposition (VD); however, solution-processed (SP) devices hold the promise for a much more cost-effective and less energy-intense fabrication. Their performance, however, lags behind 2 vacuum-deposited devices, in part because there is poor control of the orientation of the transition dipole moment (TDM) of the emitter in the SP-OLED, leading to lower external quantum efficiencies. Liquid crystals (LC) have long-range order and thus introduce molecular anisotropy in films. LC multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters have been designed to enhance the preferential alignment of the TDM in the horizontal direction. However, neat films of LC MR-TADF lose the attractive photophysical properties of the isolated molecules due to aggregation caused quenching (ACQ). Herein, we propose a strategy of host:guest films wherein both the host and guest are LC. Firstly, we developed the LC host, mCPLC, which showed a high triplet energy of 2.73 eV and exhibited the smectic A (SmA) mesophase from 121 °C to 180 °C as its neat film. Upon doping the LC MR-TADF emitter DiKTa-Meso into mCPLC at concentrations of 1, 2, and 5 wt%, the SmA mesophase is retained. Spin-coated films containing 5 wt% DiKTa-Meso in mCPLC showed a high photoluminescence quantum yield (ΦPL) of 75% and a modest preferential horizontal orientation of the transition dipole moment (TDM), with an anisotropy factor (a) of 0.30. The SP-OLED fabricated using 5 wt% DiKTa-Meso in mCPLC achieved a maximum external quantum efficiency (EQEmax) of 12.2% and a low efficiency roll-off, with an EQE of 11.8 % at 1000 cd m-2.

Molecular geometry is a powerful lever for steering excited-state dynamics in thermally activated delayed fluorescence (TADF) systems. We present a modular phthalimide-based emitter platform that systematically decouples donor planarity and donor-acceptor (D-A) connectivity to sculpt distinct excited-state topologies. By combining planar (2D) or non-planar (3D) donors with direct or phenylene-bridged linkages, we realize a tunable progression of photophysical behavior-from prompt fluorescence and phosphorescence to fast and locally excited (LE)-mediated slow TADF. Quantum-chemical calculations reveal how structural modulation governs singlet-triplet energy gap (Delta E ST) and enables vibronic coupling between 3CT and 3LE states. Time-resolved spectroscopy confirms a crossover from an effective three-state description to 3LE-involving, multi-state reverse intersystem crossing (rISC) pathways. OLEDs fabricated with the most decoupled emitter reach state-of-the-art efficiencies for phthalimide-based TADF systems (EQEmax approximate to 36%) and exhibit pronounced horizontal dipole orientation (anisotropy factor a approximate to 0.16). Together, these results establish direct links between molecular conformation/connectivity, excited-state topology, and device-level performance within an imide-based platform, providing valuable structure-property relations for tuning TADF kinetics.

Electrochemiluminescence (ECL) produces light through electrochemical reactions and has shown promise for various analytic applications in biomedicine. However, the use of ECL devices (ECLDs) as light sources has been limited due to insufficient light output and low operational stability. In this study, we present a high-power pulsed operation strategy for ECLDs to address these limitations and demonstrate their effectiveness in optogenetic manipulation. By applying a biphasic voltage sequence with short opposing phases, we achieve intense and efficient ECL through an exciplex-formation reaction pathway. This approach results in an exceptionally high optical power density, exceeding 100 microW/mm2, for several thousand pulses. Balancing the ion concentration by optimizing the voltage waveform further improves device stability. By incorporating multiple optimized pulses into a burst signal separated by short rest periods, extended light pulses of high brightness and with minimal power loss over time were obtained. These strategies were leveraged to elicit a robust optogenetic response in fruit fly (Drosophila melanogaster) larvae expressing the optogenetic effector CsChrimson. The semi-transparent nature of ECLDs facilitates simultaneous imaging of larval behaviour from underneath, through the device. These findings highlight the potential of ECLDs as versatile optical tools in biomedical and neurophotonics research.

Abstract Used extensively in sensing applications, the application of solution-state electrochemiluminescent devices (ECLDs) in lighting and displays has been constrained by their low luminance and short operational lifetime. Here, we introduce ECLDs based on electrochemically induced hyperfluorescence (ECiHF), and demonstrate their use in a calligraphic display. We use the double-decker arrangement assumed by the electron donor and acceptor segments of the molecule TpAT-tFFO to realize thermally activated delayed fluorescence from an electrogenerated charge-transfer excimer state. ECLDs based on this strategy achieve improved efficiency, a luminance of >6200 cd m−2 and their operational lifetime is more than 10-fold longer than all previous ECLDs with meaningful efficiency or brightness. Using spectroelectrochemical analysis, we identify energy level alignment between excimer and emitter as a crucial factor for efficient ECiHF. Our findings highlight the potential of ECiHF for improving ECLDs and pave the way to commercial applications of this form of fluid light.

Microcavities can be used to narrow the broad emission spectra of OLED displays—but at the cost of angular dependence. Polaritons solve this issue and enable angle‐independent and highly efficient OLED emissions.

Controlling the spin state of a molecule using the spatiotemporal properties of visible light is of interest for spintronic devices in information technology or (bio)medical applications. We, herein, report an all-organic visible light-induced photochromic system than can switch from a diamagnetic (singlet) to a paramagnetic (triplet) state. This is realized by precisely tuning orbital symmetry and internal molecular strain in a [5]helicene scaffold substituted with an indanedione π-acceptor. Irradiation with visible light at cryogenic temperatures gives a kinetically meta-stable paramagnetic diradical state with a solvent-dependent ground-state multiplicity (triplet or singlet), which can be thermally switched back to its initial diamagnetic state.

Nucleic acid sensing is crucial for advancing diagnostics, therapeutic monitoring, and molecular biology research by enabling the precise identification of DNA and RNA interactions. Here, we present an innovative sensing platform based on DNA-functionalized whispering gallery mode (WGM) microlasers. By correlating spectral shifts in laser emission to changes in the refractive index, we demonstrate real-time detection of DNA hybridization and structural changes. The addition of gold nanoparticles to the DNA strands significantly enhances sensitivity, and exclusively labeling the sensing strand or a hairpin strand eliminates the need for secondary labeling of the target strand. We further show that ionic strength influences DNA compactness, and we introduce a hairpin-based system as a dual-purpose sensor and controlled release mechanism for drug delivery. This versatile WGM-based platform offers promise for sequence-specific nucleic acid sensing, multiplexed detection, and in vivo applications in diagnostics and cellular research.

Micro- and nanoplastics pose a growing threat to marine organisms, such as reef-building corals. Yet, our understanding of microplastic uptake, interaction with coral tissue, and incorporation into coral skeletons remains limited, mainly due to the invasiveness of existing methods for detecting microplastics. Here, we exploit optical resonances in polymer spheres to transform microplastic particles into microscopic lasers. The bright, distinctive, and stable spectral signatures emitted by the microscopic laser particles function as optical barcodes, allowing extended tracking of microplastics transport through optically opaque coral tissue. Simultaneously, the lasers provide real-time sensing of dynamic changes at the microplastic surface with nanoscale resolution. Using confocal hyperspectral imaging, we establish the technical and analytical framework to capture coral anatomy and combine tracking and surface sensing into an integrated, non-invasive approach. With this, we explore the transport and internalization of individual microplastics in live corals, opening new avenues for understanding their ecological impact.

Laser light is one of the greatest and most versatile technologies ever invented. Recent developments in the miniaturization of lasers have opened up the possibility of directly interfacing living biological cells with microscopic lasers. The significantly greater brightness and spectral finesse of such biointegrated microlasers, relative to the fluorescent markers commonly used in biomedical research, have enabled numerous applications centered around cellular barcoding and biochemical and biophysical sensing. It further enables measurements in deeper tissue and with greater distinguishability. Here, we review the current state of this quickly growing field, starting with a brief recapitulation of its origins. We describe the prevalent cavity strategies and material systems used, the procedures for ensuring efficient biointegration of lasers, and the instrumentation developed for rapid analysis of light generated by biointegrated lasers, which requires high-resolution hyperspectral imaging. We discuss how the characteristics of biointegrated microlasers are highly applicable to research requiring multiplexed optical barcoding and sensing of cellular dynamics deep in highly scattering tissue. Finally, we share our vision for the future of this nascent field of biophotonics, list the most important challenges that will need to be addressed, and summarize emerging strategies in related areas that may be of particular benefit to the field of biointegrated microlasers. (c) 2025 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Magnetoelectric transducers are being investigated as a promising alternative for wireless power transfer in cases where small device size and/or low operation frequency are desired. To maximize the output power of such transducers, operation at their mechanical resonance frequency is imperative. However, a reduction in size along the direction of oscillation is intrinsically accompanied by an increase in resonance frequency. Here, we report on a computational shape optimization strategy to minimize the resonance frequency in magnetoelectric transducers by ≈38% within a set of given optimization constraints. We show that our algorithm can be used to guide the design of magnetoelectric transducers optimized to operate at different resonance frequencies and allows for consistent frequency spacing between transducers, thus enabling separately addressable devices and clustered operation. Finally, we propose four needle-shaped devices that could be used as bioimplants that impose minimal tissue damage upon direct insertion into tissue. The increase in resonance frequency associated with the needle shape is overcompensated by a frequency minimization step. Our work paves the way for computationally guided resonance frequency tuning in the field of magnetoelectric transducers.

Organic biluminescence, the simultaneous emission from both the singlet and triplet excited state manifolds, is a rare and incompletely understood emission process. However, biluminescent compounds have wide-reaching applications, such as in sensing, anti-counterfeiting, and optoelectronics, owing to the complex interplay of excited states having distinct spectral profiles and lifetimes. Herein, the biluminescence of a family of polycyclic aromatic heterocycles known as nitrogen-containing indolocarbazoles ( NICz ) is described. As 1 wt.% doped films in polymethylmethacrylate (PMMA), these compounds exhibit dual fluorescence/room temperature phosphorescence (RTP) with λ PL in the near-UV ( ≈ 375 nm) and green ( ≈ 500 nm), respectively, and remarkably long phosphorescence lifetimes extending into the multi-second regime. This RTP is shown to persist even at doping concentrations as low as 0.1 wt.%. Additionally, two of the emitters exhibit multi-resonant thermally activated delayed fluorescence (MR-TADF)/RTP biluminescence, which, to the best of knowledge, would be the first examples of such behavior. Finally, insight is provided into the dependence of these competing emission pathways on the temperature and concentration, with supporting wavefunction-based computations.

Focal segmental glomerulosclerosis (FSGS) is a histologic lesion caused by a variety of injurious stimuli that lead to dysfunction/loss of glomerular visceral epithelial cells (i.e., podocytes). Pathogenic mutations in crumbs homolog-2 (CRB2), encoding the type 1 transmembrane protein crumbs homolog-2, have been shown to cause early-onset corticosteroid-resistant nephrotic syndrome (SRNS)/FSGS. Here, we identified a two-generation Indian kindred (DUK40595) with biopsy-proven SRNS/FSGS caused by a compound heterozygous mutation in CRB2 comprised of the previously described truncating mutation p.Gly1036_Alafs*43 and a rare 9-bp deletion mutation p.Leu1074_Asp1076del. Because compound heterozygous mutations involving the truncating p.Gly1036_Alafs*43 variant have been associated with reduced CRB2 expression in podocytes and autosomal recessive SRNS/FSGS, we sought to define the pathogenic effects of CRB2 deficiency in podocytes. We show that CRB2 knockdown induces yes-associated protein (YAP) activity and target gene expression in podocytes. It upregulates YAP-mediated mechanosignaling and increases the density of focal adhesion and F-actin. Using elastic resonator interference stress microscopy (ERISM), we demonstrate that CRB2 knockdown also enhances podocyte contractility in a substrate stiffness-dependent manner. The knockdown effect decreases with increasing substrate stiffness, indicating impaired mechanosensing in CRB2 knockdown cells at low substrate stiffness. Although the mechanical activation of CRB2 knockdown cells is associated with increased YAP activity, the enhanced cell contractility is not significantly reduced by the selective YAP inhibitors K-975 and verteporfin, suggesting that multiple pathways may be involved in mechanosignaling downstream of CRB2. Taken together, these studies provide the first evidence that CRB2 deficiency may impair podocyte mechanotransduction via disruption of YAP signaling in podocytes.NEW & NOTEWORTHY We identified a rare compound heterozygous CRB2 mutation as the cause of familial SRNS/FSGS in a two-generation East Asian kindred. Modeling the effect of the mutation, we show that CRB2 knockdown in podocytes induces YAP transcriptional activity and upregulates YAP-mediated mechanosignaling. Using elastic resonator interference stress microscopy (ERISM), we demonstrate that CRB2 knockdown enhances podocyte contractility in a substrate stiffness-dependent manner. The knockdown effect decreases with increasing substrate stiffness, indicating impaired mechanosensing in CRB2-deficient podocytes.