Dinara Samigullina, P. Will, L. Galle, Simone Lenk, J. Grothe, S. Kaskel, S. Reineke
{"title":"Parameter optimization of light outcoupling structures for high-efficiency organic light-emitting diodes","authors":"Dinara Samigullina, P. Will, L. Galle, Simone Lenk, J. Grothe, S. Kaskel, S. Reineke","doi":"10.1063/5.0022497","DOIUrl":"https://doi.org/10.1063/5.0022497","url":null,"abstract":"Organic light-emitting diodes (OLEDs) have successfully entered the display market and continue to be attractive for many other applications. As state-of-the-art OLEDs can reach an internal quantum efficiency (IQE) of almost 100 %, light outcoupling remains one of the major screws left to be turned. The fact that no superior outcoupling structure has been found underlines that further investigations are needed to understand their prospect. In this paper, we use two-dimensional titanium dioxide (2D TiO$_2$) block arrays as a model of an internal light outcoupling structure and investigate the influence of its geometrical parameters on achieving the highest external quantum efficiency (EQE) for OLEDs. The multivariable problem is evaluated with the visual assistance of scatter plots, which enables us to propose an optimal period range and block width-to-distance ratio. The highest EQE achieved is 45.2 % with internal and external structures. This work contributes to the highly desired prediction of ideal light outcoupling structures in the future.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"22 11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77826766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Romero-Garc'ia, N. Jim'enez, J. Groby, A. Merkel, Vincent Tournat, G. Theocharis, O. Richoux, V. Pagneux
{"title":"Perfect Absorption in Mirror-Symmetric Acoustic Metascreens","authors":"V. Romero-Garc'ia, N. Jim'enez, J. Groby, A. Merkel, Vincent Tournat, G. Theocharis, O. Richoux, V. Pagneux","doi":"10.1103/physrevapplied.14.054055","DOIUrl":"https://doi.org/10.1103/physrevapplied.14.054055","url":null,"abstract":"Mirror-symmetric acoustic metascreens producing perfect absorption independently of the incidence side are theoretically and experimentally reported in this work. The mirror-symmetric resonant building blocks of the metascreen support symmetric and antisymmetric resonances that can be tuned to be at the same frequency (degenerate resonances). The geometry of the building blocks is optimized to critically couple both the symmetric and the antisymmetric resonances at the same frequency allowing perfect absorption of sound from both sides of the metascreen. A hybrid analytical model based on the transfer matrix method and the modal decomposition of the exterior acoustic field is developed to analyze the scattering properties of the metascreen. The resulting geometry is 3D printed and experimentally tested in an impedance tube. Experimental results agree well with the theoretical predictions proving the efficiency of these metascreens for the perfect absorption of sound in the ventilation problems.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74162045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Dubrovsky, Morgan G. Blevins, S. Boriskina, Diedrik Vermeulen SiPhox Inc., Cambridge, Ma, Usa, M. I. O. Technology
{"title":"High Contrast Probe Cleavage Detection","authors":"M. Dubrovsky, Morgan G. Blevins, S. Boriskina, Diedrik Vermeulen SiPhox Inc., Cambridge, Ma, Usa, M. I. O. Technology","doi":"10.1364/FIO.2020.JTU7C.3","DOIUrl":"https://doi.org/10.1364/FIO.2020.JTU7C.3","url":null,"abstract":"Photonic biosensors that use optical resonances to amplify biological signals associated with the adsorption of low-index biological markers offer high-sensitivity detection capability, real-time readout, and scalable low-cost fabrication. However, they lack inherent target specificity and can be sensitive to temperature variations and other noise sources. In this letter, we introduce a concept of the High Contrast Probe Cleavage Detection (HCPCD) mechanism, which makes use of the dramatic optical signal amplification caused by cleavage of large numbers of high-contrast nanoparticle labels instead of the adsorption of low-index biological molecules. We illustrate numerically the HCPCD detection mechanism with an example of a silicon ring resonator as an optical transducer with gold and silicon nanoparticles as high-contrast labels. Simulations show that it is possible to detect a single cleavage-event by monitoring spectral shifts of micro-ring resonances. Furthermore, detection specificity and signal amplification can be achieved through the use of collateral nucleic acid cleavage caused by enzymes such as CAS12a and CAS13 after binding to a target DNA/RNA sequence.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78025704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elaine Carroll, Darragh Buckley, D. McNulty, C. O’Dwyer
{"title":"Communication—Conductive Paintable 2D Layered MoS2 Inks","authors":"Elaine Carroll, Darragh Buckley, D. McNulty, C. O’Dwyer","doi":"10.1149/2162-8777/abc1c0","DOIUrl":"https://doi.org/10.1149/2162-8777/abc1c0","url":null,"abstract":"Conductive and paintable inks of 2D layered MoS2 with aspect ratio-dependent conductivity are demonstrated. Using ultrasonically assisted solvent-exfoliation of MoS2, 2D and few-layer suspensions become inks that provide smooth films when painted. Conductivity of painted 2D MoS2 inks can be modulated by length and width, where the aspect ratio dependence of conductivity is linked to the painting direction. Inks of solvent-exfoliated MoS2 can be painted as conductive films without polymeric additives.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82283729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperature dependence of reconfigurable bandstop filters using vanadium dioxide switches","authors":"A. Muller, M. Cavalieri, A. Ionescu","doi":"10.1063/5.0021942","DOIUrl":"https://doi.org/10.1063/5.0021942","url":null,"abstract":"In this letter we report and investigate the temperature dependency of various radio frequency parameters (RF) for a fabricated reconfigurable bandstop filter with vanadium dioxide (VO2) switches measured up to 55 GHz. Here the insulator to metal (ITM) and metal to insulator transition (MIT) hysteresis of the VO2 thin film influence on the RF characteristics of the filters is analyzed from 25 °C and 120 °C in heating and cooling. The resonance frequency and maximum insertion loss (IL) stability and sensitivity with temperature variations are explored. It is noticed that increasing the temperature with 50 °C from 25 °C (or decreasing it with 50 °C from 120 °C) will result in a less than 1% fractional frequency shift in respect to the off and on resonance frequencies. The sharp DC conductivity levels variations of the VO2 thin film around the transition temperatures translate into sharp effects on the resonance characteristics of the filters. On the contrary, the maximum IL levels are less sensitive to the DC films sharp conductivity changes around the VO2 transition temperature. Last, we see that the RF parameters in heating and cooling at 80 °C, above (but close to) the DC transition temperatures of VO2 exhibit completely different resonance frequencies. The RF results reported close to the transition temperatures for the VO2 thin films can diverge in heating and cooling, thus of a more insightful understanding of VO2 reconfigurable RF devices has to include temperature dependent measurements at various temperatures below MIT and ITM in the RF ranges too","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89248054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Urban, F. Gity, P. Hurley, N. McEvoy, A. Di Bartolomeo
{"title":"Isotropic conduction and negative photoconduction in ultrathin PtSe2 films","authors":"F. Urban, F. Gity, P. Hurley, N. McEvoy, A. Di Bartolomeo","doi":"10.1063/5.0021009","DOIUrl":"https://doi.org/10.1063/5.0021009","url":null,"abstract":"PtSe$_2$ ultrathin films are used as the channel of back-gated field-effect transistors (FETs) that are investigated at different temperatures and under super-continuous white laser irradiation. The temperature-dependent behavior confirms the semiconducting nature of multilayer PtSe$_2$, with p-type conduction, a hole field-effect mobility up to 40 cm2/(Vs) and significant gate modulation. Electrical conduction measured along different directions shows isotropic transport. A reduction of PtSe$_2$ channel conductance is observed under exposure to light. Such negative photoconductivity is explained by a photogating effect caused by photo-charge accumulation in SiO$_2$ and at the Si/SiO$_2$ interface.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87735486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Modica, R. Zhu, R. Horváth, G. Beaudoin, I. Sagnes, R. Braive
{"title":"Slow propagation of 2 GHz acoustical waves in a suspended GaAs phononic waveguide on insulator","authors":"G. Modica, R. Zhu, R. Horváth, G. Beaudoin, I. Sagnes, R. Braive","doi":"10.1063/5.0019949","DOIUrl":"https://doi.org/10.1063/5.0019949","url":null,"abstract":"Optoelectronic oscillators have dominated the scene of microwave oscillators in the last few years thanks to their great performances regarding frequency stability and phase noise. However, miniaturization of such a device is an up to date challenge. Recently, devices based on phonon-photon interaction gather a lot of interest thanks to their extreme compactness and working frequency directly in the GHz. In this frame, a still missing element to obtain long-term frequency stability performances is an on-chip delay within the feedback loop. Here, we experimentally show filtering and slow propagation of 2 GHz acoustic waves on a Gallium Arsenide membrane heterogeneously integrated on silicon wafer. By engineering the dispersion of an acoustical waveguide, we evidence a group velocity below 1000 m/s for the mode able to propagate. Thus, an integrated delay implementation is at reach for potential improvement of opto-acoustic devices such as optomechanical oscillators or wireless applications.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91311846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felix M. Mayor, Wentao Jiang, Christopher J. Sarabalis, T. McKenna, J. Witmer, A. Safavi-Naeini
{"title":"Gigahertz Phononic Integrated Circuits on Thin-Film Lithium Niobate on Sapphire","authors":"Felix M. Mayor, Wentao Jiang, Christopher J. Sarabalis, T. McKenna, J. Witmer, A. Safavi-Naeini","doi":"10.1103/PHYSREVAPPLIED.15.014039","DOIUrl":"https://doi.org/10.1103/PHYSREVAPPLIED.15.014039","url":null,"abstract":"Acoustic devices play an important role in classical information processing. The slower speed and lower losses of mechanical waves enable compact and efficient elements for delaying, filtering, and storing of electric signals at radio and microwave frequencies. Discovering ways of better controlling the propagation of phonons on a chip is an important step towards enabling larger scale phononic circuits and systems. We present a platform, inspired by decades of advances in integrated photonics, that utilizes the strong piezoelectric effect in a thin film of lithium niobate on sapphire to excite guided acoustic waves immune from leakage into the bulk due to the phononic analogue of index-guiding. We demonstrate an efficient transducer matched to 50 ohm and guiding within a 1-micron wide mechanical waveguide as key building blocks of this platform. Putting these components together, we realize acoustic delay lines, racetrack resonators, and meander line waveguides for sensing applications. To evaluate the promise of this platform for emerging quantum technologies, we characterize losses at low temperature and measure quality factors on the order of 50,000 at 4 kelvin. Finally, we demonstrate phononic four-wave mixing in these circuits and measure the nonlinear coefficients to provide estimates of the power needed for relevant parametric processes.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"85 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87407587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Charge-pumping with finger capacitance in a custom electrostatic energy harvesting ASIC","authors":"A. Y. Zhou, M. Maharbiz","doi":"10.1063/5.0014008","DOIUrl":"https://doi.org/10.1063/5.0014008","url":null,"abstract":"We present an integrated circuit capable of scavenging energy from repetitive changes in finger touch capacitance. A finger tapping on this ASIC generates a capacitive change of approximately 770pF. These changes feed into a charge-pump circuit which stores 320pJ of energy on a 1nF storage capacitor. We present measurement results and simulations that demonstrate operation. As a proof-of-concept, we also demonstrate that the harvested energy can power a ring oscillator which outputs a series of chirps with frequencies ranging from 80Hz to 30kHz as the storage capacitor voltage charges and discharges.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86984049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Attiaoui, É. Bouthillier, G. Daligou, A. Kumar, S. Assali, O. Moutanabbir
{"title":"Extended Short-Wave Infrared Absorption in Group-IV Nanowire Arrays","authors":"A. Attiaoui, É. Bouthillier, G. Daligou, A. Kumar, S. Assali, O. Moutanabbir","doi":"10.1103/PHYSREVAPPLIED.15.014034","DOIUrl":"https://doi.org/10.1103/PHYSREVAPPLIED.15.014034","url":null,"abstract":"Engineering light absorption in the extended short-wave infrared (e-SWIR) range using scalable materials is a long-sought-after capability that is crucial to implement cost-effective and high-performance sensing and imaging technologies. Herein, we demonstrate enhanced, tunable e-SWIR absorption using silicon-integrated platforms consisting of ordered arrays of metastable GeSn nanowires with Sn content reaching 9 at.% and variable diameters. Detailed simulations were combined with experimental analyses to systematically investigate light-GeSn nanowire interactions to tailor and optimize the nanowire array geometrical parameters and the corresponding optical response. The diameter-dependent leaky mode resonance peaks are theoretically predicted and experimentally confirmed with a tunable wavelength from 1.5 to 2.2 {mu}m. A three-fold enhancement in the absorption with respect to GeSn layers at 2.1 {mu}m was achieved using nanowires with a diameter of 325 nm. Finite difference time domain simulations unraveled the underlying mechanisms of the e-SWIR enhanced absorption. Coupling of the HE11 and HE12 resonant modes to nanowires is observed at diameters above 325 nm, while at smaller diameters and longer wavelengths the HE11 mode is guided into the underlying Ge layer. The presence of tapering in NWs further extends the absorption range while minimizing reflection. This ability to engineer and enhance e-SWIR absorption lays the groundwork to implement novel photonic devices exploiting all-group IV platforms.","PeriodicalId":8423,"journal":{"name":"arXiv: Applied Physics","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74681301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}