Advanced Photonics Research最新文献

{"title":"Key Factors in Achieving High Responsivity for Graphene-Based Terahertz Detection","authors":"Long Xiao,&nbsp;Riccardo Degl’Innocenti,&nbsp;Zhiping Wang","doi":"10.1002/adpr.202300272","DOIUrl":"https://doi.org/10.1002/adpr.202300272","url":null,"abstract":"<p>Terahertz (THz) radiation is highly promising for various applications, from industrial inspections to medical diagnoses. Given the typically ultralow-level power of generated THz radiation, the achievement of high responsivity in THz detection stands as a critical imperative for its applications. Graphene-based detectors have become an attractive choice for THz detection due to the graphene unique 2D material structure, allowing a broad absorption spectrum and ultrafast response. Various plasmonic antenna arrays are also employed to couple with graphene, compensating for its modest optical absorption. However, the configuration of the plasmonic antenna arrays plays a crucial role in THz detection as it determines the graphene physical mechanisms of photodetection, directly impacting the final responsivity. Here, the key factors for achieving high responsivity are investigated and it is presented that reducing the gap size of the plasmonic antenna arrays to the nanoscale and implementing a series-connection configuration can result in a remarkable increase in responsivity, often by several orders of magnitude. Importantly, this approach effectively prevents short circuits and minimizes dark current, further enhancing the overall performance of the detection system.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300272","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141968215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Two-Stage Polymerization Strategy for Preparing Polymer-Network Liquid Crystals with Oxygen-Sensing Property","authors":"Zongdai Liu,&nbsp;Zhibo Zhang,&nbsp;Yi Zhang,&nbsp;Dan Luo,&nbsp;Kun-Lin Yang","doi":"10.1002/adpr.202300340","DOIUrl":"https://doi.org/10.1002/adpr.202300340","url":null,"abstract":"<p>Polymer-network liquid crystal (PNLC) possesses both advantages of low-molecular-weight liquid crystal (LMWLC) and liquid crystal (LC) polymer. Herein, a two-stage polymerization strategy for the formation of unique PNLC with oxygen-sensing properties is reported. The reaction mixture consists of 6% diacrylate RM257, 93.5% LMWLC 4-cyano-4′-pentylbiphenyl (5CB), and 0.5% photoinitiator dimethoxy-2-phenylacetophenone (DMPA). In the first stage, the mixture is exposed to UV light for 2 min to form a primary polymer network, which is highly uniform with a planar orientation. However, some free radicals are trapped inside the LC due to the short UV exposure time. Subsequently, the trapped free radicals are released by heating the PNLC sample into an isotropic state. Under this condition, the free radicals can move freely and react with surrounding monomers to form a secondary polymer network, which is highly disordered and scatters light strongly. Because oxygen can deactivate free radicals trapped inside the PNLC, the phenomenon to detect oxygen and monitor the diffusion of oxygen through the PNLC is exploited. The PNLC-based oxygen sensor is potentially useful for the detection of oxygen and monitoring the exposure time to oxygen.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300340","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142165796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of Quantum Efficiency in Perovskite Solar Cells Through Whispering Gallery Modes from Titanium Oxide Micro-Resonators","authors":"Ayusmin Panda,&nbsp;Chandran Sudakar,&nbsp;Birabar Ranjit Kumar Nanda","doi":"10.1002/adpr.202300339","DOIUrl":"https://doi.org/10.1002/adpr.202300339","url":null,"abstract":"&lt;p&gt;With the aid of 3D full-field finite difference time–domain simulations, model configurations for &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;CsPbI&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$left(text{CsPbI}right)_{3}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; thin-film solar cell devices that include periodically arranged &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;TiO&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$left(text{TiO}right)_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; microspheres, exhibiting resonating whispering gallery modes (WGMs), are proposed. The &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;TiO&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$left(text{TiO}right)_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; microspheres present, either immersed in perovskite or coated with perovskite layer, between the electron- and hole-transport layers show enhanced current-conversion efficiency. The presence of WGMs lead to enhancement in the absorption of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;CsPbI&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$left(text{CsPbI}right)_{3}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; layer. The incoming electromagnetic wave couples with &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mtext&gt;TiO&lt;/mtext&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$left(text{TiO}right)_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; microsphere and forms confined resonating modes. Different designs are examined for deciding the appropriate position of WGM exhibiting spheres with respect to thin-film perovskite solar cell (PSC) featuring back reflector and optimized antireflectance coating. Since the incoupling element is lossless, energy stored in microspheres is absorbed efficiently by the underlying active material. This directly contributes to the ","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 9","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300339","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142165742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Terahertz Pseudo-Waveform-Selective Metasurface Absorber Based on a Square-Patch Structure Loaded with Linear Circuit Components","authors":"Yongzhi Cheng,&nbsp;Rui Xing,&nbsp;Fu Chen,&nbsp;Hui Luo,&nbsp;Ashif Aminulloh Fathnan,&nbsp;Hiroki Wakatsuchi","doi":"10.1002/adpr.202300303","DOIUrl":"https://doi.org/10.1002/adpr.202300303","url":null,"abstract":"<p>\u0000In recent years, metasurfaces composed of lumped nonlinear circuits have been reported to exhibit the capability of detecting specific electromagnetic waves, even when the waves are of the same frequency, depending on their respective waveforms or, more precisely, their pulse widths. Herein, three types of metasurface absorbers (MSAs) are presented which are composed of a square-patch structure loaded with linear circuit components, including lumped resistors or resistors in parallel with capacitors/inductors, which can mimic the waveform-selective absorption behavior in the terahertz (THz) region. By judiciously selecting suitable values for the linear circuit components, these MSAs can achieve near-perfect absorption of incident continuous waves or longer pulses while exhibiting reduced absorption of short pulses at the same THz frequency. These linear circuit structures can be referred to as pseudo-waveform-selective MSAs because their waveform-selective absorption characteristics are primarily derived from the dispersion behavior of the resonator structures, as opposed to the frequency conversion commonly observed in nonlinear circuits. These outcomes and discoveries introduce an additional degree of freedom for waveform discrimination in the THz frequency range, potentially enabling a broader range of applications, including but not limited to detection, sensing, and wireless communication.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300303","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141968216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lensless Imaging Based on Dual-Input Physics-Driven Neural Network","authors":"Jiale Zuo,&nbsp;Ju Tang,&nbsp;Mengmeng Zhang,&nbsp;Jiawei Zhang,&nbsp;Zhenbo Ren,&nbsp;Jianglei Di,&nbsp;Jianlin Zhao","doi":"10.1002/adpr.202400029","DOIUrl":"https://doi.org/10.1002/adpr.202400029","url":null,"abstract":"<p>Lensless imaging, as a novel computational imaging technique, has attracted great attention due to its simplicity, compactness, and flexibility. This technique analyzes and processes the diffraction of an object to obtain complex amplitude information. However, traditional algorithms such as Gerchberg-Saxton (G–S) algorithm tend to exhibit significant errors in complex amplitude retrieval, particularly for edge information. Additional constraints have to be incorporated on top of amplitude constraints to enhance the accuracy. Recently, deep learning has shown promising results in optical imaging. However, it requires a large amount of training data. To address these issues, a novel approach called dual-input physics-driven network (DPNN) is proposed for lensless imaging. DPNN utilizes two diffractions recorded at different distances as inputs and uses an unsupervised approach that combines physical imaging model to reconstruct object information. DPNN adopts a U-Net 3+ architecture with a loss function of mean absolute error (MAE) to better capture diffraction features. DPNN achieves highly accurate reconstruction without requiring extensive data and being immune to background noise. Based on different diffraction intervals, noise levels, and imaging models, DPNN exhibits superior capabilities in peak signal-to-noise ratio and structural similarity compared with conventional methods, effectively achieving accurate phase or amplitude information reconstruction.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 11","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202400029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silicon-Based 850 nm GaAs/GaAsP-Strained Quantum Well Lasers with Active Region Dislocation Blocking Layers","authors":"Jian Li,&nbsp;Chen Jiang,&nbsp;Hao Liu,&nbsp;Yang Zhang,&nbsp;Hao Zhai,&nbsp;Xin Wei,&nbsp;Qi Wang,&nbsp;Gang Wu,&nbsp;Chuanchuan Li,&nbsp;Xiaomin Ren","doi":"10.1002/adpr.202300348","DOIUrl":"https://doi.org/10.1002/adpr.202300348","url":null,"abstract":"<p>A silicon-based room temperature (RT) continuous wave (CW) operation quantum well (QW) laser emitting at 850 nm is reported in this article. By applying the dislocation filter superlattice, the threading dislocation density of the GaAs pseudosubstrate on Si is reduced to 1.8 × 10⁷ cm⁻². The metal-organic chemical vapor deposition-grown laser structure with GaAs/GaAsP QW and InAlAs active region dislocation blocking layer are fabricated into broad-stripe Fabry–Perot laser diodes. A typical threshold current and threshold current density of 286 mA and 715 Acm⁻² are obtained with 2 mm cavity length and 20 um stripe width samples. A 94.2 mW single-facet output power lasing around 854 nm and a 0.314 WA⁻¹ slope efficiency is measured under RT CW operation. After a 10-min aging process, the tested laser can operate stably under continuous operation conditions at RT and the lifetime can be approximated using an exponential fitting curve, indicating a good life reliability of this QW laser.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 7","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300348","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141565861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing SiGe–SiO2 Visible–Short-Wave Infrared Photoresponse by Modulating Interplay Between Strain and Defects Through Annealing","authors":"Muhammad Taha Sultan,&nbsp;Ionel Stavarache,&nbsp;Andrei Manolescu,&nbsp;Unnar Bjarni Arnalds,&nbsp;Valentin Serban Teodorescu,&nbsp;Halldor Gudfinnur Svavarsson,&nbsp;Snorri Ingvarsson,&nbsp;Magdalena Lidia Ciurea","doi":"10.1002/adpr.202300316","DOIUrl":"https://doi.org/10.1002/adpr.202300316","url":null,"abstract":"<p>SiGe-SiO₂-based structures present high interest for their high photosensitivity from visible to short-wavelength infrared. Herein, two postdeposition annealing procedures, that is, rapid thermal annealing (RTA) and rapid-like furnace annealing (FA), are compared. Both RTA and FA are performed at 600 °C for 1 min for SiGe nanocrystals (NCs) formation in SiO₂ matrix in Si/SiO₂/SiGe/SiO₂ structures deposited by magnetron sputtering. The FA imitates RTA resulting in enhanced spectral response. X-ray diffraction, transmission electron microscopy, and Raman spectroscopy are carried out showing Ge-rich SiGe NCs with 11.3 ± 1.2 nm size for RTA and 9.4 ± 0.8 nm for FA. Photocurrent spectra for both structures show several peaks that are annealing dependent. The photocurrent intensity for FA samples is ≈7 times higher than RTA samples while cutoff wavelengths are slightly different, that is, 1365 nm for FA and 1375 nm for RTA. The FA structures show (at −1.5 V) over 4 A W⁻¹ responsivity at 730 nm, 6.4 × 10⁷ Jones detectivity at 735 nm, and 2.2 × 10⁷ Jones at about 1210 nm. FA structures contain small SiGe NCs with incorporated residual strain, while RTA ones are formed of columnar SiGe NCs separated by SiGeO_<i>x</i> amorphous regions and show increased tensile strain in the SiGe.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300316","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of tert-Butylation on the Photophysics of Thermally Activated Delayed Fluorescence Emitters","authors":"Kalyani Thakur,&nbsp;Bas van der Zee,&nbsp;Oskar Sachnik,&nbsp;Constantin Haese,&nbsp;Robert Graf,&nbsp;Jasper J. Michels,&nbsp;Gert-Jan A. H. Wetzelaer,&nbsp;Charusheela Ramanan,&nbsp;Paul W. M. Blom","doi":"10.1002/adpr.202400022","DOIUrl":"https://doi.org/10.1002/adpr.202400022","url":null,"abstract":"<p>Thermally activated delayed fluorescence (TADF) emitters potentially can provide organic light-emitting diodes with 100% internal quantum efficiency by harvesting triplet excitons. Generally, TADF emitters are small molecules that are not applicable for solution processability. The addition of <i>tert</i>-butyl groups to the periphery of TADF emitters has proven to improve their solubility in various organic solvents, reduce aggregation-induced quenching, and enhance the photoluminescence quantum yield (PLQY). This article studies the photophysical influence of the <i>tert</i>-butyl group attached to an emitter with a carbazole acceptor and a triazine donor. The resulting t3CzTrz-F is a blue–green TADF emitter, in which the addition of a <i>tert</i>-butyl group increases the rate of reverse intersystem crossing (rISC), while simultaneously decreasing the nonradiative decay rate substantially. In addition, dilution of t3CzTrz-F in a host matrix in film results in an enhanced PLQY, which is associated with a decrease in the nonradiative decay constant, while there is no change in the rISC rate. Through a solid-state NMR study, the change in rISC and nonradiative rate upon <i>tert</i>-butylation by enlarged intermolecular spacing and reduced vibrational and rotational freedom is rationalized, resulting in improved photophysical performance.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 11","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202400022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142579638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Widening the Gamut of Structural Colors of Gold via Insulator–Metal Bilayer Coatings","authors":"Md Abdur Rahman,&nbsp;Simon Wredh,&nbsp;Darya Burak,&nbsp;Joel K. W. Yang,&nbsp;So-Hye Cho,&nbsp;Seung Yong Lee,&nbsp;Sang Hoon Kim,&nbsp;Ji Young Byun","doi":"10.1002/adpr.202300324","DOIUrl":"https://doi.org/10.1002/adpr.202300324","url":null,"abstract":"<p>\u0000Tuning the color of Au has been a longstanding problem in the luxury industry. Conventional approaches, involving Au alloying, compromise purity and demand distinct alloy compositions for each hue. This study demonstrates a lithography-free method for generating structural colors on a gold surface by adjusting the thickness of titanium dioxide, a high-index dielectric. While color tuneability is limited if TiO₂ is coated directly on the Au surface, a range of vivid colors can be generated if a 50−100 nm thick AuAl₂ underlayer is used. AuAl₂, an accepted alloy for purple gold, broadens the color gamut, providing a protective coating without diminishing gold purity. The reflectance dip of the bilayer structure exhibits a significant red shift with increasing thickness of the TiO₂ layer, allowing diverse colors by TiO₂ insulator tuning. Simulation studies corroborate experimental results, affirming that coating a TiO₂ layer on the AuAl₂ underlayer yields a wide range of colors. This method, based on thin-film interference, shows promise for widespread use, offering a broad spectrum of structural colors in an industry striving for diverse Au color representation.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Upconversion of Infrared Light by Graphitic Microparticles Due to Photoinduced Structural Modification","authors":"Rohin Sharma,&nbsp;Nishma Bhattarai,&nbsp;Rijan Maharjan,&nbsp;Lilia M. Woods,&nbsp;Nirajan Ojha,&nbsp;Ashim Dhakal","doi":"10.1002/adpr.202300326","DOIUrl":"https://doi.org/10.1002/adpr.202300326","url":null,"abstract":"<p>Recent reports of upconversion and white light emission from graphitic particles warrant an explanation of the physics behind the process. A model is offered, wherein the upconversion is facilitated by photoinduced electronic structure modification allowing for multiphoton processes. As per the prediction of the model, it is experimentally shown that graphite upconverts infrared light centered around 1.31 μm (0.95 eV) to broadband white light centered around 0.85 μm (1.46 eV). The results suggest that upconversion from shortwave infrared (≈3 μm, 0.45 eV) to visible region may be possible. The experiments show that the population dynamics of the electronic states involved in this upconversion process occur in the timescale of milliseconds.</p>","PeriodicalId":7263,"journal":{"name":"Advanced Photonics Research","volume":"5 8","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/adpr.202300326","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}