Ultraviolet Photoelectron Spectroscopy Measurements Research Articles

First-Principles Investigation on Work Function of Martensitic Carbon Steels: Effect of Interstitial Carbon on Anodic Dissolution Resistance

The effect of interstitial carbon on the work function and the dissolution resistance of martensitic carbon steels was investigated. Ultraviolet photoelectron spectroscopy measurements of 0.001%C, 0.44%C, and 0.88%C specimens showed that the work function of steels increased with the amount of interstitial carbon. In addition, first-principles calculations indicated that the presence of interstitial carbon clearly increased the work function on both the (110) and (100) orientation surfaces. The immersion tests and potentiodynamic polarization measurements of the specimens were conducted in 50 mM C 8 H 5 KO 4 at pH 4.0, and it was clarified that the anodic dissolution reaction was suppressed as the amount of interstitial carbon increased. The improvement in work function appeared to be related to the superior anodic dissolution resistance.

(Invited) Surface Ligands for Methylammonium Lead Iodide Perovskites and Their Impact on Interfacial Energetics, Material Stability, and Photovoltaic Performance

Surface ligand treatment of organic metal halide perovskites can improve material and device stability, alter interfacial energetics, and increase perovskite solar cell (PSC) performance. Unlike in traditional inorganic semiconductors such as silicon, surface ligands often penetrate into the perovskite crystal and result in the formation of reduced dimensionality structures (where the 3D perovskite framework is broken into 2D sheets of varying thickness). Such ligand penetration can have a large impact on the surface energetics and material stability; thus, it is important to understand how surface ligand structure impacts ligand penetration. Using angle-dependent x-ray photoelectron spectroscopy (XPS) and x-ray diffraction we show that surface ligands with ammonium and phosphonic acid binding groups often penetrate into MAPbI3. This ligand penetration can significantly influence surface energetics, as probed with ultraviolet and inverse photoelectron spectroscopy measurements. The observed changes in surface energetics upon surface ligand treatment have a large impact on the PSC performance, with better photovoltaic performance arising for ligands that result in more favorable energy landscapes for electron transfer from MAPbI3 to the electron transport layer, C60. For a series of ammonium containing ligands, we find that both the cross-sectional area and extent of ligand fluorination impact the penetration of the surface ligand into the perovskite. Furthermore, surface ligands with larger cross-sectional areas result in improved MAPbI3 stability.

Edge assisted epitaxy of CsPbBr3 nanoplates on Bi2O2Se nanosheets for enhanced photoresponse

Bi2O2Se has been proved to be a promising candidate for electronic and optoelectronic devices due to their unique physical properties. However, it is still a great challenge to construct the heterostructures with direct epitaxy of hetero semiconductor materials on Bi2O2Se nanosheets. Here, a two-step chemical vapor deposition (CVD) route was used to directly grow the CsPbBr3 nanoplate-Bi2O2Se nanosheet heterostructures. The CsPbBr3 nanoplates were selectively grown on the Bi2O2Se nanosheet along the edges, where the dangling bonds provide the nucleation sites. The epitaxial relationships between CsPbBr3 and Bi2O2Se were determined as [200]Bi2O2Se||[110]CsPbBr3 and [110]Bi2O2Se||[200]CsPbBr3 by transmission electron microscopy characterization. The photoluminescence (PL) results reveal that the formation of heterostructures results in the remarkable PL quenching due to the type-I band arrangement at CsPbBr3/Bi2O2Se interface, which was confirmed by ultraviolet photoelectron spectroscopy (UPS) and Kelvin probe measurements, and makes the photogenerated carriers transfer from CsPbBr3 to Bi2O2Se. Importantly, the photodetectors based on the heterostructures exhibit a 4-time increase in the responsivity compared to those based on the pristine Bi2O2Se sheets, and the fast rise and decay time in microsecond. These results indicate that the direct epitaxy of the CsPbBr3 plates on the Bi2O2Se sheet may improve the optoelectronic performance of Bi2O2Se based devices.

Optimization of the U parameter in CoO groupings in ZnO [formula omitted] and [formula omitted] surfaces: A DFT+U and UPS study

Cobalt oxide groupings in ZnO surface structures were studied using density functional theory within the Hubbard-like U (DFT+U) formalism to calculate the total energy of several configurations of this system. We find the U parameter by fitting the calculated density of states (DOS) to ultraviolet photoelectron spectroscopy measurements of pristine and doped ZnO nanostructures. It was found that the most energetically favorable configuration in the Co-doped ZnO nanostructures are clusters of CoO.

Regulating electronic structure and adsorptivity in molybdenum selenide for boosting electrocatalytic water splitting

Rationally designing highly efficient, cost-effective electrocatalysts towards overall water splitting to substitute noble-metal-based catalysts currently is still an outstanding challenge for renewable energy conversion. Herein, we demonstrate multiscale regulation of MoSe2 by CoSe tailoring for achieving significantly increased activity as a bifunctional electrocatalyst for highly efficient overall water splitting. X-ray absorption near-edge structure (XANES) and ultraviolet photoelectron spectroscopy (UPS) measurements unravel electron transfer from CoSe to MoSe2 as well as the increase of atomic disorder degree and the decrease of coordination number for MoSe2, thus facilitating efficient and fast interfacial charge transport and meanwhile providing more electrocatalytic active sites. Moreover, the introduced CoSe species not only improves the water adsorption/dissociation capability of MoSe2 by providing additional water adsorption sites, which is crucial for subsequent fast H2 generation, but also promotes MoSe2 to realize bifunctional behavior. Besides, density functional theory (DFT) calculations further reveal that CoSe modification for MoSe2 could evidently tailor d-band center of MoSe2 and accordingly significantly reduce hydrogen-adsorption Gibbs free energy (ΔGH*) of MoSe2 from 0.78 to 0.16 eV, along with an enhanced electronic conductivity owing to the increased electronic states near the Fermi level based on density of states (DOSs). This work gives a deeper insight for the relationship between multiscale regulation strategy and intrinsic activity of materials.

A Study of Interfacial Electronic Structure at the CuPc/CsPbI2Br Interface

In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.

Interfacial Charge Transfer Induced Electronic Property Tuning of MoS2 by Molecular FunctionalizationSupported by the National Natural Science Foundation of China (Grant No. 22002031), the Natural Science Foundation of Zhejiang Province (Grant No. LY18F010019), and the Innovation Project in Hangzhou for Returned Scholar.

The modulation of electrical properties of MoS2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices. Herein, interfacial charge transfer induced electronic property tuning of MoS2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements. A downward band-bending of MoS2-related electronic states along with the decreasing work function, which are induced by the electron transfer from Cs overlayers to MoS2, is observed after the functionalization of MoS2 with Cs, leading to n-type doping. Meanwhile, when MoS2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F 4-TCNQ), an upward band-bending of MoS2-related electronic states along with the increasing work function is observed at the interfaces. This is attributed to the electron depletion within MoS2 due to the strong electron withdrawing property of F 4-TCNQ, indicating p-type doping of MoS2. Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS2 and paves the way to optimize its performance in electronic and optoelectronic devices.

Insights into the sputter-instigated valence plasmon oscillations in CIGSe thin films

We report a unique methodology of triggering plasmonic excitations in sputtered ultrathin CIGSe films. In this approach of plasmonic excitation, secondary ion source present in the growth system instigates the formation of nanoclusters of its constituent elements, which is the source of plasmonic excitation. The formation of the nanoclusters during the growth is because of the distinct sputtering out rates of the various elements during the growth. For the verification of valence electron excitation and plasmonic oscillations, the studies performed as follows: a) investigation of electron energy loss from the ultraviolet-photoelectron spectroscopy measurements, b) quantification of the various electron energy loss contributions associated with the constituent element present in the films within the observed broad peaks in ultravoilet photoelectron spectroscopy (UPS) spectrum, c) estimation of particular plasmon contribution, i.e., particle, valence-surface, and valence-bulk plasmon at the air/thin-film interface, and within the thin film, d) verification of plasmonic behavior by analyzing different optical properties performing spectroscopic ellipsometry measurements, 5) validation of the nanocluster emergence in ultrathin CIGSe thin films deploying Field Emission Scanning Electron Microscopy. This approach is promising in terms of improving the solar cell performance parameters by supplementing the optical path length within the absorber in the broad spectral range without the need of externally supplied metal nanoparticles.

Work function modulation of graphene with binary mixture of Cu and C60F36

Graphene is a promising candidate for flexible, transparent electrodes in organic electronic devices. In order to achieve enhanced device performance, work function (WF) modulation of graphene for better electric contact at the electrode/active materials interface is of significant importance. Herein, we have demonstrated the effective modulation of graphene WF with binary mixture of Cu and C60F36 and the highest WF of ∼6.04 eV is obtained after in situ thermal annealing at 150 °C. The ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) measurement indicate that the growth of Cu on C60F36-modified graphene leads to C–F bonds breaking of C60F36 and the formation of Cu–F bonds on the basal plane of graphene, which is responsible for the large WF increase of graphene. The mechanism for the WF increase of binary mixture of Cu and C60F36 modified graphene (BMG) has been corroborated by density-functional theoretical (DFT) calculations, which shows that the C–F bond breaking of C60F36 is facilitated by Cu adatoms, and the WF increase can be attributed to the formation of surface dipole layer with the direction pointing from vacuum to graphene, which is consistent with UPS and XPS results. Moreover, our results indicate that other 3d transition metal adatoms (Ti, V, Fe, Co, and Ni) on graphene can also facilitate the C–F bond breaking of C60F36 and the formation of surface dipole layer, resulting in the WF increase of graphene.

Enhanced Hole‐Carrier Selectivity in Wide Bandgap Halide Perovskite Photovoltaic Devices for Indoor Internet of Things Applications

AbstractHalide perovskite‐based photovoltaic (PV) devices have recently emerged for low energy consumption electronic devices such as Internet of Things (IoT). In this work, an effective strategy to form a hole‐selective layer using phenethylammonium iodide (PEAI) salt is presented that demonstrates unprecedently high open‐circuit voltage of 0.9 V with 18 µW cm−2 under 200 lux (cool white light‐emitting diodes). An appropriate post‐deposited amount of PEAI (2 mg) strongly interacts with the perovskite surface forming a conformal coating of PEAI on the perovskite film surface, which improves the crystallinity and absorption of the film. Here, Kelvin probe force microscopy results indicate the diminished potential difference across the grain boundaries and grain interiors after the PEAI deposition, constructing an electrically and chemically homogeneous surface. Also, the surface becomes more p‐type with a downshift of a valence band maximum, confirmed by ultraviolet photoelectron spectroscopy measurement, facilitating the transport of holes to the hole transport layer (HTL). The hole‐selective layer‐deposited devices exhibit reduced hysteresis in light current density–voltage curves and maintain steadily high fill factor across the different light intensities (200–1000 lux). This work highlights the importance of the HTL/perovskite interface that prepares the indoor halide perovskite PV devices for powering IoT device.

Direct growth of tungsten disulfide on gallium nitride and the photovoltaic characteristics of the heterojunctions

Photovoltaic device construct with a 2D nanomaterial atop a 3D wide bandgap semiconductor enables van Hove singularity induced enhanced light absorption on the front surface in close proximity (few atoms above) to the depletion region. Here, thin layers of tungsten disulfide (WS2) varying from mono to few layers were grown directly on both n-gallium nitride (GaN) and p-GaN via low pressure chemical vapor deposition. The conditions for WS2 growth were optimized for a larger coverage of the GaN substrate. The WS2 film was characterized using confocal Raman spectroscopy and x-ray photoelectron spectroscopy. Ultraviolet photoelectron spectroscopy measurement was conducted to elucidate the electronic band structures of WS2 on top of GaN. Afterwards, WS2/GaN heterojunction photovoltaic devices were fabricated. The current density–voltage (J–V) tests were conducted to illustrate the electrical performance. The device showed an open circuit voltage of 0.53 mV and a short circuit current density of 60 µA cm−2, 85% higher than that of a WS2/Si solar cell. An external quantum efficiency was measured to be near 60% for red and infrared, and above 50% in the violet region.

N-type charge transport in heavily p-doped polymers.

It is commonly assumed that charge-carrier transport in doped π-conjugated polymers is dominated by one type of charge carrier, either holes or electrons, as determined by the chemistry of the dopant. Here, through Seebeck coefficient and Hall effect measurements, we show that mobile electrons contribute substantially to charge-carrier transport in π-conjugated polymers that are heavily p-doped with strong electron acceptors. Specifically, the Seebeck coefficient of several p-doped polymers changes sign from positive to negative as the concentration of the oxidizing agents FeCl3 or NOBF4 increase, and Hall effect measurements for the same p-doped polymers reveal that electrons become the dominant delocalized charge carriers. Ultraviolet and inverse photoelectron spectroscopy measurements show that doping with oxidizing agents results in elimination of the transport gap at high doping concentrations. This approach of heavy p-type doping is demonstrated to provide a promising route to high-performance n-type organic thermoelectric materials.

Investigation on performance of CdTe solar cells with CdS and bilayer ZnS / CdS windows grown by thermal evaporation technique

This paper primarily focuses on the performance enhancement of cadmium sulfide/cadmium telluride (CdS/CdTe) solar cells by replacing CdS window with zinc sulfide (ZnS)/CdS bilayer window. The comparative analysis of ther�mally evaporated CdS and ZnS/CdS heterostructure-based CdTe solar cells was done by employing structural, morphological, optical, and electrical analy�sis. Core objective of the work was to reduce the absorption loss at window layer by widening the total transmittance of window system for CdTe absorber. In addition, interface behavior was studied using advanced spectroscopic tech�niques, which help to analyze the diffusion. For the first time, to the best of our knowledge, ultraviolet photoelectron spectroscopy measurement has been employed on all the layers of the present superstrate structure to estimate the energy band diagram. Further, their suitability in a multi-layer graded bandgap structure was correlated to the final device parameters, concerning economic viability. Along with the fill factor increment (55% to 73%) offered by the ZnS/CdS bilayer window, limitation posed by the single-layer CdS win�dow has been discussed. Replacement of CdS by ZnS/CdS bilayer window has enhanced the conversion efficiency from 3.73% to 7.12%.

Efficient cathode contacts through Ag-doping in multifunctional strong nucleophilic electron transport layer for high performance inverted OLEDs

This paper presents an efficient and stable green inverted organic light emitting diode (IOLED) using multifunctional and strong nucleophilic quality electron transport material (1,3-bis(2-phenyl-1,10-phenanthrolin-4-yl)benzene ( m -bPPhenB)) with silver (Ag) as an n -dopant. By the energy level alignment study using in-situ ultraviolet photoelectron spectroscopy measurement, negligible electron injection barrier between indium tin oxide (ITO) and Ag-doped m -bPPhenB (Φ e ≈ 0.03 eV) is observed and the electrons can be easily tunneled from ITO into Ag-doped m -bPPhenB layer. Also, Ag dopant forms coordination bonds with phenanthroline based unit, which improves electron injection from ITO. Fabricated IOLED devices using an Ag-doped m -bPPhenB have an extremely low driving voltage of 3.6 V and external quantum efficiency of 29.0%. Such good performances of IOLED are attributed to negligible electron injection barrier at the interface between ITO and Ag-doped m -bPPhenB. The Ag-doped IOLED device also shows a good air stability owing to the stable Ag n -dopant. The doping of Ag into special electron transport layer in the IOLED structure could be applicable to various displays and lighting applications. • We fabricated efficient and stable green IOLEDs by using m -bPPhenB:Ag ETL. • A negligible electron injection barrier observed between ITO and m -bPPhenB:Ag. • IOLED showed low driving voltage, high EQE, and good stability.

Studies on Carrier Recombination in GaN/AlN Quantum Dots in Nanowires with a Core-Shell Structure.

GaN quantum dots embedded in nanowires have attracted much attention due to their superior optical properties. However, due to the large surface-to-volume ratio of the nanowire, the impacts of surface states are the primary issue responsible for the degradation of internal quantum efficiency (IQE) in heterostructured dot-in-nanowires. In this paper, we investigate the carrier recombination mechanism of GaN/AlN dot-in-nanowires with an in situ grown AlN shell structure. Ultraviolet photoelectron spectroscopy (UPS) measurements were performed to describe the band bending effect on samples with different shell thicknesses. Temperature-dependent photoluminescence (TDPL) data support that increasing the AlN shell thickness is an efficient way to improve internal quantum efficiency. Detailed carrier dynamics was analyzed and combined with time-resolved photoluminescence (TRPL). The experimental data are consistent with our physical model that the AlN shell can effectively flatten the band bending near the surface and isolate the surface non-radiative recombination center. Our systematic research on GaN/AlN quantum dots in nanowires with a core–shell structure may significantly advance the development of a broad range of nanowire-based optoelectronic devices.

Two-dimensional Bi2OS2 doping improves the performance and stability of perovskite solar cells

• 2D Bi 2 OS 2 nanosheets are introduced as additives into the perovskite active layer. • Addition of 0.02 mg/ml 2D Bi 2 OS 2 increases power conversion efficiency (PCE) of perovskite solar cells (PVSCs). • The lifetime of optimized PVSCs is also prolonged due to addition of 2D Bi 2 OS 2 . • 2D Bi 2 OS 2 assist the formation of highly crystalline of perovskite thin film. • 2D Bi 2 OS 2 nanosheets can suppress the uncoordinated Pb 2+ ions trap states through Pb-S bond. Additive engineering has been proved to be an effective method to increase the performance of perovskite solar cells (PVSCs) by increasing the quality of the perovskite thin film. Two-dimensional (2D) Bi 2 OS 2 nanomaterial is an excellence optoelectronic material because of its tunable direct band gap, ultra-high charge mobility, wide absorption range and high absorption coefficient. In this work, 2D Bi 2 OS 2 nanosheets are synthesized and introduced as additives into the perovskite precursor solution to adjust the film formation process for the first time. Serving as heterogeneous nucleation site, 2D Bi 2 OS 2 can reduce the nucleation barrier and assist the formation of highly crystalline and crystal orientation along the (1 1 0) plane perovskite thin film, which is beneficial to improve the mobility and lifetime of charge carriers. Besides, X-ray photoelectron spectroscopy (XPS) measurement reveals that 2D Bi 2 OS 2 nanosheets can interact with Pb 2+ within the perovskite through Pb-S bond, thus suppressing the uncoordinated Pb 2+ ions trap states. Scanning electron microscope (SEM) demonstrates 2D Bi 2 OS 2 nanosheets can fill up the pin-holes and grain boundaries on the perovskite film surface. Ultraviolet photoelectron spectroscopy (UPS) measurement indicates that the valence band (VB) of optimized perovskite film is 0.28 eV upshifted closer to the highest occupied molecular orbital (HOMO) of the hole transport layer (HTL), which accelerates the charge transportation at perovskite/HTL interface. Consequently, the average power conversion efficiency (PCE) of 18.96% (highest PCE of 19.89%) is achieved upon incorporating 2D Bi 2 OS 2 nanosheets with an optimized concentration of 0.02 mg/ml into MAPbI 3 precursor solution, which is greatly improved compared to the average PCE of 15.71% for the control devices (highest PCE of 16.77%). Besides, the lifetime of optimized PVSCs is also prolonged due to the less defect states and better perovskite film quality. This work not only provides a facile method to increase the PCE and stability of PVSCs, but also reveals 2D Bi 2 OS 2 material has potential applications in PVSCs.

All‐Vacuum‐Processing for Fabrication of Efficient, Large‐Scale, and Flexible Inverted Perovskite Solar Cells

Vacuum deposition of transporting layers, especially the hole‐transporting layer (HTL), is still a big challenge for the fabrication of large‐area perovskite solar cells (PSCs). In this work, efficient and large‐area PSCs are fabricated by thermal evaporation of all the layers. Poly(bis(4‐phenyl)(2,4,6‐trimethylphenyl)amine) (PTAA) is used as the HTL, and a compact layer of PTAA with low thickness (2–10 nm) is successfully deposited using thermal evaporation. The optical and ultraviolet photoelectron spectroscopy (UPS) measurements prove that the evaporated PTAA has a great match with the single A‐cation methylammonium triiodide perovskite film in terms of quenching effect and band alignment. After fabrication of the inverted architecture using all‐vacuum‐processing, PSCs with power conversion of efficiencies (PCEs) of 19.4% for small area (0.054 cm2) and 18.1% for large area (1 cm2) are achieved, which are higher than those of solution‐based devices. A flexible PSC with PCE of 17.27% is also fabricated using this approach. Moreover, the fabricated PSCs, using the vacuum technique, show negligible hysteresis and good stability, better than the devices fabricated on spin‐coated PTAA. This work highlights the potential of vacuum deposition for scale‐up and commercialization of PSCs.

Energy band diagram for SiO2/Si system as evaluated from UPS analysis under vacuum ultraviolet with variable incident photon energy

We have studied the energy band diagram for the Si surface and SiO2/Si system by using ultraviolet photoelectron spectroscopy (UPS) measurements. In the UPS measurements, monochromatized vacuum ultraviolet with variable incident photon energies below 10.50 eV was used in order to increase the detection limit of the depth from the surface and to understand the electronic states not only at the surface but also in the region near the interface of the stacked structure. From the incident photon energy dependence of the UPS spectral width, the energy level of the valence band top of the H-terminated Si surface and the electrical potential change in the SiO2/Si structure has been evaluated. Also, the vacuum work function value of the hetero-epitaxial Ag(111) surface has been investigated to check this measurement technique.

A cyano-rich small molecule dopant for organic thermoelectrics

Abstract The development of new dopants makes a great contribution to the recent advances in organic semiconductors. In this work, a cyano-rich small molecule, i.e., octacyano[4]dendralene containing bis-1,1,4,4-tetracyanobutadiene unit (TCBD), was used as a p-dopant of organic thermoelectric devices attributed to it being strongly electron-accepting and its high chemical stability. Poly(3,4-ethylenedioxythiophene) (PEDOT) was successfully doped by the TCBD dopant, and the degree of doping was comprehensively characterized by ultraviolet–visible–near infrared (UV–Vis–NIR), Fourier transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM) images, ultraviolet photoelectron spectroscopy (UPS) and X-ray photoelectron spectroscopy (XPS) measurements. The PEDOT:TCBD complex achieved its best electrical conductivity and power factor when the TCBD concentration was 18 mol%. Furthermore, a practical thermoelectric generator was constructed by the combination of the p-type PEDOT:TCBD complex and n-type constantan.

Improvement of OLED performances by applying annealing and surface treatment on electro-deposited CuSCN hole injection layer

In this study, we demonstrated an organic light-emitting diode (OLED) using electro-deposited CuSCN as a hole-injection layer. The effects of thermal annealing and UV-Ozone treatments on ITO/CuSCN/organic interfaces were investigated. By employing both UV-O3 and proper thermal annealing (75 ° C, 20 min), Cu2O was found on the surface of CuSCN. With these treatments, the surface roughness of the organic deposited on CuSCN was reduced from 4.25 to 1.28 nm. The optical transmittance was also enhanced. Additionally, the CuSCN surface energy and polarity were considerably increased and the hole-injection barrier was decreased from 0.70 to 0.47 eV. The interface dipole effects lead to better adhesion between CuSCN/organic interface and facilitate the hole injection capability from anode ITO due to the formation of superficial Cu2O. The underlying mechanisms were illustrated by surface energy, X-Ray photoelectron spectroscopy (XPS), and ultraviolet photoelectron spectroscopy (UPS) measurements. As a result, these significantly enhanced CuSCN characteristics led to improved OLED performances, which achieved a hundred-fold efficiency compared to the device without any treatment. With this realization of integrating electro-deposited CuSCN into conventional organic optoelectronic systems, it could bring various practical benefits particularly concerning industrial interests in low-temperature, cost-effective, and large-area fabrication techniques.