Device Applications Research Articles

Renewable Musa Sapientum derived porous nano spheres for efficient energy storage devices

Biomass-based carbonaceous materials derived from Musa Sapientum have gained much attention in recent years for their application in energy storage devices, especially supercapacitors. In the present work, we synthesized carbonaceous material from banana peel as the biomass precursor by using a pyrolysis method carried out at various temperatures (600, 800, and 1000 °C). The characterization of the prepared carbonaceous materials BP600, BP800 and BP1000 was done by using different characterization techniques such as FTIR, XRD, FE-SEM, and TEM, studies. The electrochemical study of the synthesized material was carried out by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) electrochemical impedance spectroscopy (EIS). The supercapacitive performance of the material was studied using a 3-electrode system with 3M KOH as an electrolyte. As a result, the BP600 exhibited a better specific capacitance with higher energy and power densities along with a maximum cyclic stability of 16,000 cycles. To show the practical applicability of the material BP 600, two electrode system studies were carried out as well, which showed preferentially good values for specific capacitance with appreciable power and energy density values. The study provides us with a green approach for the fabrication of non-toxic, low-cost, and environmentally friendly potential porous carbonaceous electrode materials by converting bio-waste into a clean and renewable source of energy.

Real-time detection of aging status of methylammonium lead iodide perovskite thin films by using terahertz time-domain spectroscopy

The inadequate stability of organic–inorganic hybrid perovskites remains a significant barrier to their widespread commercial application in optoelectronic devices. Aging phenomena profoundly affect the optoelectronic performance of perovskite-based devices. In addition to enhancing perovskite stability, the real-time detection of aging status, aimed at monitoring the aging progression, holds paramount importance for both fundamental research and the commercialization of organic–inorganic hybrid perovskites. In this study, the aging status of perovskite was real-time investigated by using terahertz time-domain spectroscopy. Our analysis consistently revealed a gradual decline in the intensity of the absorption peak at 0.968 THz with increasing perovskite aging. Furthermore, a systematic discussion was conducted on the variations in intensity and position of the terahertz absorption peaks as the perovskite aged. These findings facilitate the real-time assessment of perovskite aging, providing a promising method to expedite the commercialization of perovskite-based optoelectronic devices.Graphical

Tough and temperature-tolerance cellulose/polyacrylic acid/bentonite hydrogel with high ionic conductivity enables self-powered triboelectric wearable electronic devices

Solid-state zinc-ion hybrid supercapacitors (ZHSCs) featuring hydrogel electrolytes have become ideal for large-scale flexible energy storage. However, existing polyacrylic acid (PAA) hydrogel electrolytes often lack the combined traits of ionic conductivity, mechanical robustness, and temperature tolerance. Herein, a versatile PAA-based hydrogel electrolyte (ACBH-Zn) containing a ZnCl2-cellulose solution and bentonite (BT) is delivered, facilitated by cooperative coordination bonds and hydrogen bonds. The coordination bonds between Zn2+ and −COOH of PAA, in conjunction with cellulose and BT, alongside the abundant hydrogen bonds within cellulose and PAA, are conducive to upgrading mechanical strength and ionic conductivity, while the BT's lamellar structure further provides sufficient ion migration channels. Consequently, the ACBH-Zn showcases exceptional mechanical properties, satisfying ionic conductivity (88.9 mS cm−1), and excellent temperature tolerance at −60 °C (30.3 mS cm−1). The ACBH-ZHSC, when assembled, attains a remarkable maximum energy density (323.4 Wh kg−1), maintaining an impressive capacity retention rate (92 %) even after undergoing 10,000 cycles at 10.0 A g−1. Furthermore, the assembled self-powered triboelectric wearable electronic device effectively converts mechanical energy from human movement into electrical energy, enabling efficient storage and utilization, and offering promising insights into the application of flexible wearable devices.

Efficient Synthesis of Metastable Cyclodextrin‐Based Polyrotaxanes with Tunable Threading Ratios

Cyclodextrin‐based polyrotaxanes (CD‐PRs) are gaining attention for their dynamic sliding rings along the polymer axis, enabling various applications in molecular shuttles, drug delivery, and durable polymers with slidable cross‐links. However, the conventional synthesis of CD‐PRs with tunable threading ratios is typically laborious, time‐consuming, and complicated, which limits their scalability and cost‐effectiveness. Herein, we highlight the great potential of planetary centrifugal mixing, a process that significantly accelerates and simplifies the initial synthesis of polypseudorotaxanes (PPRs), followed by a thiol‐ene click reaction as an efficient end‐capping reaction for the synthesis of PRs. Notably, PRs synthesized with glutathione (GSH) as the end‐capping reagent are in a metastable state, where GSH act as a molecular bumper that significantly prevent de‐threading of α‐CD rings at room temperature. Moreover, the rate of ring de‐threading can be precisely controlled by heating, enabling the preparation of metastable PRs with tunable threading ratios over a wide range. The developed strategy is of great significance to the efficient synthesis of CD‐PRs, thus marking a significant step towards their practical application in advanced functional materials and devices.

Interplay between Structural, Electronic, and Magnetic Properties in the p0-d Semi-Heusler Compounds: The Case of Li-Based Compounds

Half-metallic semi-Heusler compounds (also known as half-Heusler compounds) are currently at the forefront of scientific research due to their potential applications in spintronic devices. Unlike other semi-Heuslers, the p0(d0)-d compounds do not appear to crystallize in the typical variant of the C1b structure. We investigate this phenomenon in the p0-d Heusler compounds LiYGa and LiYGe, where Y varies between Ca and Zn, using first-principles ab initio electronic band-structure calculations. We examine the electronic and magnetic properties of these compounds in relation to the three possible C1b structures. Notably, LiVGa, LiVGe, LiMnGa, and LiCrGe are half-metallic ferromagnets across all three variations of the C1b lattice structure. Our findings will serve as a foundation for future experimental studies on these compounds.

Structure Factors Design of Liquid Crystal Beam Steering Device for Augmented Reality Applications

Structure Factors Design of Liquid Crystal Beam Steering Device for Augmented Reality Applications

Digital Light Processing Resins with Programmable Shape Memory for Biomedical Applications.

The creation of biodegradable and biocompatible shape memory polymers amenable to biofabrication techniques remains a challenge. The ability to create shape-changing biodegradable objects that are triggered at body temperature opens up possibilities in tissue engineering, minimally invasive surgery, and actuating bioimplants. Merging Digital Light Processing (DLP) printing with shape memory polymers brings us closer to new smart biomedical outcomes. Previously, we developed a poly(caprolactone-co-trimethylenecarbonate) urethane acrylate resin for the DLP fabrication of biodegradable 3D objects. In further studies, we observed that some of these resins possessed shape memory properties, triggered by body temperature (37 °C). In this subsequent study, we explored the shape memory properties and tunability of this resin family via changes in copolymer composition, molecular weight, and identity of the acrylate end-capping unit. We found that we could create a library of shape memory resins, amenable to DLP printing, which allowed the creation of shape-actuating structures with some tunability over the speed of shape memory and mechanical properties. We observed that increased mole fraction of caprolactone in the copolymer and increased molecular weight of the polymer led to a decrease in speed of the shape memory switch. Furthermore, we observed a trade-off between the composition and the end-capping moiety on the mechanical properties of the polymers. These polymeric resins were able to be processed into shapes that were able to perform work, including the release of cargo and grabbing/lifting of an object. This platform now provides a way to tune the speed and mechanical properties of a shape memory DLP object created from common and scalable polymerization techniques. This work ultimately provides a new platform to develop customizable and biodegradable devices capable of actuating and delivery devices for numerous biomedical applications.

Thickness-modulated electronic band structures and exciton behavior of non-van-der-waals 2D Bi2O2Se films

Bi2O2Se, as a non-van-der-waals (non-vdW) interlayer coupling two-dimensional material, its electronic band structures and exciton behavior still merit further in-depth studies, especially in the consideration of thickness tuning degrees of freedom. Here, we reveal the broadband excitonic performance and critical point properties of Bi2O2Se films with different thicknesses (3.54–16.33 nm). Five critical points are determined and assigned to specific optical transitions. Moreover, we observe that electronic bandstructures in the Γ valley are stable with variable thicknesses, while the deeper electron levels received more pronounced thickness modulation. And we first report four excitons in wide spectral range (1.24–6.20 eV) through absorption coefficient fitting. Significantly, due to the strong localization of electrons and holes induced by the intralayer built-in electric field, the exciton binding energy (Eb) value of 3.54 nm-Bi2O2Se (234 meV at Γ position) is apparently larger than typical multi-layer TMDCs, which offering unprecedented opportunities in applications in optoelectronic devices. Furthermore, Eb of two excitons at low energy region (Eb1, Eb2) red-shift with increasing thickness, while Eb of higher-energy excitons (Eb3, Eb4) blue-shift, owing to the dispersion characteristic of the effect dielectric screening effects. Our results are vital to wide-ranging applications of Bi2O2Se from fundamental science to optoelectronic devices.

Luminescence and spectroscopic studies on Dy3+-Eu3+ doped SiO2-B2O3-ZnO-La2O3-BaO glass for WLED

A series of SiO2-B2O3-ZnO-La2O3-BaO (SBZLBa) glasses doped with Dy3+ and Eu3+ were synthesized using the melt-quenching technique. Their optical characteristics and potential applications in W-LED devices were investigated. The structural effects resulting from doping the glass with Dy3+ and Eu3+ ions were elucidated through infrared spectroscopy and an examination of the physical properties. The variations in emission intensity within the fluorescence spectrum validated the sensitizing effect of Dy3+ on Eu3+ within the glass matrix. By manipulating the transitions of both Dy3+ and Eu3+, the excitation wavelength was altered, enabling the realization of cool white, neutral white, and warm white luminescence, thus accommodating the diverse requirements for white light emission in lighting applications. After incorporating 1.0 mol% of Dy2O3 and 0.8 mol% of Eu2O3, respectively, the glass exhibited CIE coordinates of (0.3332, 0.3535), positioning it within the white light spectrum and in close proximity to the ideal white light coordinates of (0.33, 0.33). The SBZLBa-Dy2O3–0.8Eu2O3 glass exhibited a quantum yield of 5.98 %. It has been demonstrated through acid and alkali resistance tests that this glass possesses excellent chemical stability. Additionally, temperature-dependent emission spectra have revealed that the luminous intensity of the glass maintains over 85 % of its room temperature value at 185 °C, with Eα determined to be 0.2387 eV.

Strain-bandgap quasi-linear correlation applied to modulation of NiBr2 monolayer optical properties

Recently, two-dimensional transition metal dihalides have shown diverse applications in spintronics, quantum devices, and optoelectronic devices. In this work, density functional theory (DFT) is adopted to investigate the effect of biaxial strain upon the electronic structure and optical properties of NiBr2 monolayer. The results show that NiBr2 is an indirect semiconductor with band gap 2.62 eV (DFT + U) and 3.18 eV (HSE06), which could vary quasi-linearly from 2.73 eV to 1.71 eV modulated by biaxial strain (6 % to −10 %). Combined with the analysis of the density of states (DOS), the primary reason for the alteration in the band gap is that strain significantly affects the behavior of Ni 3d electrons. When the strain changes from positive to negative, the DOS of Ni 3d shifts towards the Fermi level, resulting in a reduction in the band gap. Within this strain range, all of the optical properties exhibit a quasi-linear tendency similar to the band gap variation. The optical peaks of NiBr2 under compressive strain are not only red-shifted into the visible light (VL) region but also significantly enhanced in the VL and ultraviolet (UV) regions. Applying strain can greatly boost the electrical and optical properties of NiBr2 monolayer, making it a promising candidate in the field of ultraviolet detectors.

Cyanoacetamide co-sensitizers DY-1 and DY-2: Unveiling a promising path to highly efficient photovoltaic devices

This paper presents a novel approach for enhancing the efficiency of dye-sensitized solar cells (DSSCs) through the co-sensitization of cyanoacetamide-based dyes DY-1 and DY-2 with N3 dye. The synthesis and characterization of DY-1 and DY-2 co-sensitizers are described and their potential applications in photovoltaic devices are investigated. The absorption properties of DY-1 and DY-2 were analyzed, revealing their efficient light absorption in the visible range. The co-sensitization of DY-1-2 with N3 dye demonstrated a significant enhancement in photovoltaic efficiency, ranging from 7.40 % to 7.92 %. The reasons for this efficiency enhancement were thoroughly analyzed and attributed to several factors. First, the combination of DY-1-2 with the N3 dye led to a broader light absorption spectrum, enabling more efficient utilization of incident photons. Additionally, co-sensitization facilitates efficient charge separation and injection processes, contributing to improved photocurrent. The acid-base co-sensitization approach further enhances the overall efficiency by maximizing the charge transfer and coverage on the semiconductor surface. This study sheds light on the development of novel sensitizers to enhance the performance of DSSCs, and the findings contribute to the advancement of photovoltaic devices.

First‐Principles Study on the Effects of Different Valence Hi and VO on the Mobility, Conductivity, and Carrier Lifetime of β‐Ga2O3: Mo5+/6+

The poor conductivity of β‐Ga2O3 limits its application in optoelectronic devices. Currently, there have been advancements in investigating the impact of Mo doping on the photoelectric characteristics of β‐Ga2O3. However, there are few studies on the impact of different valence states of Mo doping and the coexistence of O vacancy and interstitial H on the electrical properties of β‐Ga2O3. In the process of preparing β‐Ga2O3, O vacancy and interstitial H inevitably exist. In response to these problems, the first‐principles GGA + U method is used to study the impact of different valence states of Mo doping and the coexistence of interstitial H and O vacancy on the electrical properties of β‐Ga2O3. The electronic structure, mobility, conductivity, and carrier lifetime of the system are calculated and analyzed. The results show that all doping systems are more stable under Ga‐rich conditions. The band gap of the Mo‐doped β‐Ga2O3 system gradually narrows, which is mainly attributed to the Burstein–Moss effect and the multiplicity reintegration effect. Mo doping effectively improves the electrical conductivity of the system. Ga47O72Mo16+H11+ system has the longest carrier lifetime; Ga47O72Mo16+H10 has the largest mobility; Ga47O72Mo15+H10 system has the highest conductivity. Therefore, Mo‐doped β‐Ga2O3 materials help to prepare new electrical performance devices.

Should the Cash Receipt System (CRS) be Implemented to Optimize Taxes in the Indonesian MSME Sector?

Research Aims: This study aims to analyze the viability of applying a Cash Receipt System (CRS) concept in supervising tax revenue from the MSMEs sector to add the consideration for implementing CRS in Indonesia using the OECD (2015) framework. Design/methodology/approach: This study uses a descriptive qualitative approach in the form of a case study conducted at the Directorate General of Taxes (DGT). The study was carried out by analyzing literature analysis, analyzing taxation data on the MSMEs sector, and analyzing interview results. The data collection method consists of secondary data through literature analysis and primary data through interviews with respondents from the DGT, Regional Revenue Agency, taxpayers in the MSMEs sector, consultants, and related associations. Research Findings: Research shows that CRS policy does not fulfill some OECD (2015) principles, especially Neutrality, Efficiency, and Equity. This research emphasizes the importance of tax education and financial literacy in the MSME sector for Indonesia's sustainability of tax revenues. Theoretical Contribution/Originality: Suggested by the OECD (2017), the study contributes to the body of knowledge regarding the application of the fiscal device to counteract tax evasion in Indonesia. Keywords: Fiscal Device, Cash Receipt, Tax Evasion, MSME

Enhanced ultra-high efficiency in high-energy–density PbHfO3-based antiferroelectric ceramics through synergistic effect design

PbHfO3-based antiferroelectric materials with the giant power density and ultrafast charge–discharge performance have exhibited the potential application in advanced pulsed power microelectronic devices. Nevertheless, the huge challenge of the large driving field of the AFE-FE phase transition (EAFE-FE) accompanied by the poor breakdown electric strength (Eb) still exists up to now and further becomes a key bottleneck restricting the simultaneous realization of high energy storage density and efficiency. Hence, we report the synergistic effect to combine the tailor ABO3 perovskite structure for minimizing the electric hysteresis and increasing bandgap width to obtain the ultrahigh Eb. Rietveld refinements of the XRD patterns and Raman spectra experiments that demonstrate the average electronegativity and a redshift with the elevated Sr content attributable to enhancing bonding energy of cation-O bonds and antipolar ordering in crystalline structure, effectively resulting in stability of the PbHfO3-based antiferroelectric structure. Meanwhile, a ultrahigh Eb of 450 kV/cm is achieved owing to optimizing the average grain size and widening bandgap width. A remarkable energy storage density of 7.29 J/cm3 and record-high energy storage efficiency of 96.40 % are achieved via synergistic effect in (Pb0.93La0.02Sr0.04)(Hf0.475Sn0.475Ti0.05)O3 (PLS4HST) ceramics under respective maximum applied field. In addition, large power density of 173.40 MW/cm3 and excellent discharge energy density of 4.90 J/cm3 as well as fast discharge rate of 166.90 ns and superior frequency stability (1 ∼ 140 Hz), along with outstanding thermal stability (25 ∼ 150°C), have been simultaneously presented in PLS4HST ceramic. These results provide a good paradigm by synergistic effect designing for exploring high-performance dielectrics to meet the demanding requirements of advanced pulsed power electronic devices.

Vanadium embedded in monolayer silicene: Energetics and proximity-induced magnetism

Using the density-functional theory approach, including Hubbard U correction, we investigate the defect structures consisting of vanadium (V) atoms embedded in a monolayer silicene. Specifically, we consider V–V atom pairs in antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic states, which are embedded in substitutional and interstitial sites. We determine the ground-state structures, formation and binding energies, electronic structures, induced magnetization, as well as the spin-exchange coupling between the V–V pair. For the substitutional vanadium atom pair, the stability of the AFM and FM spin configurations depends on the sublattice sites in which the V atoms are sited. When the V pair is located on a similar sublattice site type, the AFM spin alignment is more energetically favored, whereas when the pair is located in a different sublattice site, the FM interactions are more stable. However, the relative stability of the AFM or FM configurations changes rapidly as the separation between the V pair increases. Regarding the interstitial-hole V–V pair configurations, the most stable structure is when the pair is at the nearest-neighbor hole sites and is in an FM alignment. Also, at larger separations, the AFM or FM hole configurations are approximately degenerate in energy. Furthermore, we elucidate on the Ruderman–Kittel–Kasuya–Yosida, direct-exchange, and the superexchange interaction mechanisms in the vanadium-embedded silicene. In addition, we estimate a Curie temperature (Tc) of up to ∼500 K for a silicene structure containing a V pair in the FM spin alignment. Such a high Tc, in addition to the stability of the material, suggests that vanadium-embedded silicene is a potential candidate material for spintronic device applications.

Optimization of fluorinated phenyl azides as universal photocrosslinkers for semiconducting polymers

Fluorinated phenyl azides (FPA) enable photo-structuring of π-conjugated polymer films for electronic device applications. Despite their potential, FPAs have faced limitations regarding their crosslinking efficiency, and more importantly, their impact on critical semiconductor properties, such as charge-carrier mobility. Here, we report that azide photolysis and photocrosslinking can achieve unity quantum efficiencies for specific FPAs. This suggests preferential nitrene insertion into unactivated C‒H bonds over benzazirine and ketenimine reactions, which we attribute to rapid interconversion between the initially formed hot states. Furthermore, we establish a structure‒activity relationship for carrier mobility quenching. The binding affinity of FPA crosslinker to polymer π-stacks governs its propensity for mobility quenching in both PM6 and PBDB-T used as model conjugated polymers. This binding affinity can be suppressed by FPA ring substitution, but varies in a non-trivial way with π-stack order. Utilizing the optimal FPA, photocrosslinking enables the fabrication of morphology-stabilized, acceptor-infiltrated donor polymer networks (that is, PBDB-T: ITIC and PM6: Y6) for solar cells. Our findings demonstrate the exceptional potential of the FPA photochemistry and offer a promising approach to address the challenges of modelling realistic molecular interactions in complex polymer morphologies, moving beyond the limitations of Flory‒Huggins mean field theory.

Critical factors for enhancing electrical performance in LaGdO3 capacitor

This study investigates the characteristics of metal/LaGdO3/Si capacitors using LaGdO3 as the dielectric material. LaGdO3 thin films were deposited using radio-frequency magnetron sputtering, and the effects of different process parameters, such as annealing temperature, electrode materials, and oxygen ratio, on the capacitance characteristics were investigated. Results showed that the presence of oxygen vacancies affects the dielectric constant, flat-band voltage, and breakdown field of LaGdO3 films. The optimal annealing temperature for the LaGdO3/Si stack was identified to be 600 °C, resulting in a dielectric constant of 13.9 and a flat-band voltage shift of 0.1 V. Introducing 10 % O2 during deposition effectively repaired oxygen vacancies in the film, while excessively high oxygen proportions resulted in a lower dielectric constant and a higher flat-band voltage shift. Moreover, the electrode material was found to affect the capacitance characteristics. The dielectric constants for Al/LaGdO3/Si, Ti/LaGdO3/Si, and Pt/Ti/LaGdO3/Si capacitors were 10.0, 16.3, and 17.3, respectively. The flat-band voltage shifts were −0.7, −0.42, and −0.03 V, with hysteresis voltages of 345, 117, and 32 mV, respectively. The Pt/Ti/LaGdO3/Si device exhibited the lowest oxide defect density, indicating superior interface quality and potentially enhanced device performance. In addition, the band diagrams for metal/LaGdO3/Si were constructed. This study demonstrates that oxygen vacancies and electrode materials are crucial factors influencing the capacitance characteristics of LaGdO3 films. The electrical properties of LaGdO3 films can be effectively improved by controlling process parameters, enhancing their potential for applications in capacitors and other electronic devices.

Designed 2D protein crystals as dynamic molecular gatekeepers for a solid-state device

The sensitivity and responsiveness of living cells to environmental changes are enabled by dynamic protein structures, inspiring efforts to construct artificial supramolecular protein assemblies. However, despite their sophisticated structures, designed protein assemblies have yet to be incorporated into macroscale devices for real-life applications. We report a 2D crystalline protein assembly of C98/E57/E66L-rhamnulose-1-phosphate aldolase (CEERhuA) that selectively blocks or passes molecular species when exposed to a chemical trigger. CEERhuA crystals are engineered via cobalt(II) coordination bonds to undergo a coherent conformational change from a closed state (pore dimensions <1 nm) to an ajar state (pore dimensions ~4 nm) when exposed to an HCN(g) trigger. When layered onto a mesoporous silicon (pSi) photonic crystal optical sensor configured to detect HCN(g), the 2D CEERhuA crystal layer effectively blocks interferents that would otherwise result in a false positive signal. The 2D CEERhuA crystal layer opens in selective response to low-ppm levels of HCN(g), allowing analyte penetration into the pSi sensor layer for detection. These findings illustrate that designed protein assemblies can function as dynamic components of solid-state devices in non-aqueous environments.

Mg2+ ion conducting Chitosan:PVP polymer blend electrolytes for electric double layer capacitor applications

Biopolymer electrolytes are prepared using Chitosan (CS) and Polyvinyl pyrrolidone (PVP) incorporated with magnesium chloride (MgCl2). The complex formation of electrolytes are confirmed by X-ray diffraction(XRD) and Fourier Transform Infrared spectrometer(FTIR) analysis. The scanning electron microscope(SEM) reveals the surface morphology and microstructure of the electrolytes while energy dispersive spectroscopy(EDS) facilitates the presence of elements. The distribution of elements are confirmed with elemental mapping analysis. DSC analysis enlightens on thermal properties, offering an understanding of phase transitions and thermal stability of the films. CS/PVP/MgCl2(50:50:25) polymer electrolyte shows higher ionic conductivity value of 5.8 × 10−4 S/cm at 30 °C and the specific capacitance value of 86.5 Fg−1 at low scan rate of 10 mVs−1. Linear Sweep Voltammetry (LSV) analysis has been used to determine the electrochemical stability window of the electrolyte and it is found to be 0.7 V. This result indicates that the CS/PVP/MgCl2 electrolyte is a suitable material for energy storage device applications.

Determination of Surface Charge Density and Charge Mapping of CYTOP Film in Air using Electrostatic Force Microscopy.

Cyclic transparent optical polymer (CYTOP), a fluoropolymer, finds a plethora of applications in microelectronic devices for sustainable energy harvesting and memory devices. By and large, these devices demand high voltage breakdown, a high dielectric constant, transparency, charge storage, and retention capabilities. Despite many efforts, comprehensive investigation of the charge distribution, retention, and discharge studies conducted on the CYTOP film at the micro-scale remains elusive. Here, we present direct quantification and mapping of surface charge on the CYTOP surface at room temperature using two different modes of advanced surface probe microscopy i.e., Kelvin probe force microscopy (KPFM) and electrostatic force microscopy (EFM). We estimated that the surface charge densities of the CYTOP film using EFM are 1.4 and 3.3 μC/cm2 for the injection of positive and negative charges, respectively. Furthermore, we determined the charge retention time for both injected positive and negative charges. We found that the retention capacity of the negative charges on the CYTOP film is much higher as compared to the positive charges. Moreover, it is also observed that injected negative charges are strongly localized on the CYTOP surface compared to the positive counterpart. Additionally, we demonstrated that charge writing is possible on the CYTOP surface using the AFM conductive tip. These results may find potential applications in energy harvesting, sensing, memory devices, security, and surveillance.