Depletion Region Research Articles

Enhanced Photoelectrochemical Activity Realized from WS2 Thin Films Prepared by RF‐Magnetron Sputtering for Water Splitting

AbstractWe report the synthesis of tungsten sulfide (WS2) films using RF‐magnetron sputtering at different RF powers. X‐ray diffraction (XRD) data confirm the hexagonal crystal structure of WS2 with an average crystallite size of ∼44.54 Å. With increased RF power, the preferred orientation of WS2 crystallites shifts from (002) to (100). Linear sweep voltammetry (LSV) was used to assess the Photoelectrochemical (PEC) activity of WS2 films. The film deposited at 150 W demonstrated the highest photocurrent density of 5.44 mA/cm2. The 150 W film also showed a lower Tafel slope of ∼0.374 V/decade, indicating superior PEC activity. Mott Schottky's (MS) analysis revealed a notable shift in the flat band potential towards the negative side, suggesting a shifting of the Fermi level towards the conduction band. WS2 film grown at 150 W demonstrated a majority charge carrier density of 6.2×1021 cm−3 and a depletion layer width of 1.54 nm. The observed low charge transfer resistance of 155 Ω contributed to the enhanced PEC activity with a relaxation time constant of 37 ms. These properties suggest that WS2 can be suitable for PEC water splitting.

ZnO/NiO Nanocomposite with Enhanced Photocatalytic H2 Production

Inorganic photocatalytic materials exhibiting a highly efficient response to ultraviolet-visible light spectrum have become a subject of widespread global interest. They offer a substantial prospect for generating green energy and mitigating water pollution. Zinc oxide (ZnO), among various semiconductors, proves advantageous for water-splitting applications due to its elevated reactivity, chemical stability, and nontoxic nature. However, its efficacy as a photocatalyst is hindered by limited light absorption capacity and swift charge carrier recombination. To improve charge separation and enhance responsiveness to ultraviolet-visible light photocatalysis, the formation of a heterojunction with another suitable semiconductor is beneficial. Thus, we employed hydrothermal route for the synthesis of the samples, which is a high-pressure method. The formations of ZnO/NiO heterostructures were revealed by scanning electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The nanocomposites were discovered to have a substantially higher photocatalytic activity for the generation of H2. The H2 production rates show that ZnO (i.e., 168.91 μmolg-1 h-1) exhibits good H2 production rates as compared to NiO (i.e., 135.74 μmolg-1 h-1). The best production rates were observed for ZN-30 (i.e., 247.56 μmolg-1 h-1) which is 1.46 times greater than ZnO and 1.82 times greater than NiO. This enhanced photocatalytic activity for ZN-30 is because of the good electron-hole pair separation due to the formation of depletion layer, suppression of fast charge recombination, and overcoming resistance corrosion.

Ion transport through short nanopores modulated by charged exterior surfaces.

Short nanopores find extensive applications, capitalizing on their high throughput and detection resolution. Ionic behaviors through long nanopores are mainly determined by charged inner-pore walls. When pore lengths decrease to sub-200nm, charged exterior surfaces provide considerable modulation to ion current. We find that the charge status of inner-pore walls affects the modulation of ion current from charged exterior surfaces. For 50-nm-long nanopores with neutral inner-pore walls, the charged exterior surfaces on the voltage (surfaceV) and ground (surfaceG) sides enhance and inhibit the ion transport by forming ion enrichment and depletion zones inside nanopores, respectively. For nanopores with both charged inner-pore and exterior surfaces, continuous electric double layers enhance the ion transport through nanopores significantly. The charged surfaceV results in higher ion current by simultaneously weakening the ion depletion at pore entrances and enhancing the intra-pore ion enrichment. The charged surfaceG expedites the exit of ions from nanopores, resulting in a decrease in ion enrichment at pore exits. Through adjustment in the width of charged-ring regions near pore boundaries, the effective charged width of the charged exterior is explored at ∼20nm. Our results may provide a theoretical guide for further optimizing the performance of nanopore-based applications, such as seawater desalination, biosensing, and osmotic energy conversion.

Understanding the Interfacial Energy Structure and Electron Extraction Process in Inverted Organic Solar Cells with Phosphine‐Doped Cathode Interlayers

Comprehensive SummaryCathode interlayers (CILs) play an essential role in achieving efficient organic solar cells (OSCs). However, the electronic structure at the electrode/CIL/active layer interfaces and the underlying mechanisms for electron collection remain unclear, which becomes a major obstacle to develop high‐performance CILs. Herein, we investigate the relationship of the electron collection abilities of four cross‐linked and n‐doped CILs (c‐NDI:P0, c‐NDI:P1, c‐NDI:P2, c‐NDI:P3) with their electronic structure of space charge region at heterojunction interface. By accurately calculating the depletion region width according to the barrier height, doping density and permittivity, we put forward that the optimal thickness of CIL should be consistent with the depletion region width to realize the minimum energy loss. As a result, the depletion region width is largely reduced from 13 nm to 0.8 nm at the indium tin oxide (ITO)/c‐NDI:P0 interface, resulting in a decent PCE of 17.7% for the corresponding inverted OSCs.

Amorphous Gallium Oxide Nanosheets with Broad Absorption and Spin Polarization for Si‐Based UV‒Vis‒NIR Photodetectors

AbstractAchieving broad light absorption and high carrier separation efficiency is crucial for wide‐bandgap semiconductors to enable broadband photodetection applications. Here, amorphous gallium oxide nanosheets feature with broad absorption and spin polarization Wis synthesized, and assembled with graphene and p‐Si, realizing UV‒vis‒NIR photodetection. Extended X‐ray absorption fine structure reveals that a‐GaOx NSs possess lower tetrahedral Ga occupation (10%) compared to crystalline β‐Ga2O3 (50%). UV‒vis‒NIR diffuse reflectance spectra and magnetic hysteresis loops demonstrate broad absorption and weak ferromagnetism of a‐GaOx NSs, respectively. Density functional theory calculation further reveals sub‐gap states and spin polarization in a‐GaOx NSs. Moreover, combined with Mott–Schottky curves, photoluminescence and time‐resolved photoluminescence spectra inferred the effective suppression of carrier recombination via spin polarization of a‐GaOx NSs. The graphene/a‐GaOx NSs/p‐Si photodetector incorporates a back‐to‐back rectifying junction, acquiring a dark current as low as 63 pA. All photogenerated carriers are in the depletion region of the photodetector favouring efficient charge separation. This photodetector exhibits a response time of τrise<60 ms and τfall<120 ms, and high specific detectivity 1013 Jones over 254–1064 nm light.

Influence of swift heavy ion irradiation on charge transport and conduction mechanisms across the interface of LaMnO3 and La0.7Ca0.3MnO3 manganites

Swift heavy ion (SHI) irradiated LaMnO3/La0.7Ca0.3MnO3 (LMO/LCMO) interfaces have been investigated to understand their charge transport and conduction mechanisms. Prominent effect of ion fluence has been discussed for the interface resistivity behaviors and metal to insulator phase transition for LMO/LCMO interfaces on the bases of lattice strain, crystalline granular state, crystalline imperfection, average grain size, grain boundary density and rms surface roughness. Field effect configuration (FEC) has been employed to study the interesting modifications in the irradiated LMO/LCMO interface resistivity under different applied electric fields to understand the depletion region, free charge carrier density, ferromagnetic phase fractions and crystal field based distortions. A Phenomenological percolation model has been employed to understand the role of phase separation in governing the charge conduction processes across LMO/LCMO interfaces.

Efficient and stable perovskite solar cells with regulated depletion region

Efficient and stable perovskite solar cells with regulated depletion region

Printed MoSe2/GaAs Photodetector Enabling Ultrafast and Broadband Photodetection up to 1.5 μm.

The development of high-performance and low-cost photodetectors (PDs) capable of detecting a broad range of wavelengths, from ultraviolet (UV) to near-infrared (NIR), is crucial for applications in sensing, imaging, and communication systems. This work presents a novel approach for printing a broadband PD based on a heterostructure of two-dimensional (2D) molybdenum diselenide (MoSe2) and gallium arsenide (GaAs). The fabrication process involves a precise technique to print MoSe2 nanoflower (NF) ink onto a prepatterned GaAs substrate. The resulting heterostructure exhibits unique properties, leveraging the exceptional electronic and optical characteristics of both GaAs and 2D MoSe2. The fabricated PD achieves an astounding on-off ratio of ∼105 at 5 V bias while demonstrating an exceptional on-off ratio of ∼104 at 0 V. The depletion region between GaAs and MoSe2 facilitates efficient charge generation and separation and collection of photogenerated carriers. This significantly improves the performance of the PD, resulting in a notably high responsivity across the spectrum. The peak responsivity of the device is 5.25 A/W at 5 V bias under 808 nm laser excitation, which is more than an order of magnitude higher than that of any commercial NIR PDs. Furthermore, the device demonstrates an exceptional responsivity of 0.36 A/W under an external bias of 0 V. The printing technology used here offers several advantages including simplicity, scalability, and compatibility with large-scale production. Additionally, it enables precise control over the placement and integration of the MoSe2 NF onto the GaAs substrate, ensuring uniformity and reliability in device performance. The exceptional responsivity across a broad spectral range (360-1550 nm) and the success of the printing technique make our MoSe2/GaAs heterostructure PD promising for future low-cost and efficient optoelectronic devices.

PV output estimation method of power distribution station area based on federated learning framework and improved transformer neural network

In contemporary distribution networks (DNs), characterized by extensive integration of distributed energy, the photovoltaic (PV) power output data from the distribution station areas become crucial for system planning and operational optimization. Since many PVs are installed behind-the-meter (BTM), it is difficult to directly obtain PV power data through measurement devices. Therefore, it is important to estimate the BTM PV power from the aggregating data that can be directly obtained. However, the existing estimation methods usually require centralized large-scale data training, which brings certain privacy leakage risks. In order to solve these problems, we propose a federated learning-based improved Transformer Neural Network strategy to estimate BTM PV generation at the community level with data privacy protection. Initially, enhanced Transformer neural networks, employing a fused-attention mechanism, are deployed to precisely delineate the solar power generation pattern. Subsequently, federated learning principles facilitate the sharing of specific parameters among multiple edge endpoints and a central server. This model bifurcates into two layers: an individual layer, where parameters are retained locally, and an exchange layer, where parameters are collectively shared and conveyed through momentum aggregation. This dual-layer structure effectively synchronizes the capture of both unique and common characteristics. The test on the Australian residential load dataset verifies the effectiveness of the proposed method.

Laser-enabled dual-state transformation on PANI:PSS/Si for wavelength-selective detection

Position-sensitive detectors are widely used in industry due to accurate sensing of changes in light position. The introduction of additional wavelength selectors can cause deviations in light position and affect the performance of the devices. In this work, an organic–inorganic heterojunction of polyaniline-poly (p-styrenesulfonic acid) (PANI:PSS)/p-Si is proposed to achieve selective detection at optical wavelengths using the lateral photovoltaic effect. The maximum reduction of sensitivity in the detection of 405 nm laser can reach up to 127.59 mV/mm, with a decrease in about 99%. When the device is exposed to blue-violet light, the absorption layer changes from a Si layer to a PANI:PSS layer, which weakens the photon utilization efficiency and charges carrier transport. The self-generated longitudinal voltage further enhances the absorption of the PANI:PSS layer for blue-violet light. PANI absorbs photon energy to generate electron–hole pairs and transitions from the reduced state to the oxidized state in the depletion region at the contact interface. The oxide layer hinders carrier separation and increases carrier recombination. Due to the inherent properties of the structure, the wavelength selection function is realized by the detector itself, enriching its original single function. The sensitivity in other light bands has been improved, including more than three times at 520 nm compared to p-Si. These results have provided the theoretical foundation for highly selective and tunable optoelectronic devices while helping to overcome the challenges of high manufacturing costs and customized application scenarios. They provide a viable solution for the intelligent development of optoelectronic devices.

Investigation of dielectric and electric modulus properties of Al/p-Si structures with pure, 3%, and 5% (graphene:PVA) by impedance spectroscopy

The Z–V measurements were performed in wide-range voltage (± 6 V), and then the real/imaginary parts of ε* (ε′, ε″), M* (M′, M″), Z* (Z′, Z″), tanδ, and σac values of the Al/p-Si structure with pure polyvinyl alcohol (PVA) (D1), 3% (D2), and 5% (D3) graphene-doped PVA interfacial-layer were calculated at four frequencies (1, 10, 100, and 1000 kHz). When the frequency in D2 and D3 structures was increased from 1 kHz to 1 MHz, the dielectric constant value changed from 32.47 to 5.12 and from 26.26 to 1.00, respectively. They have a strong frequency dependence due to the presence of interface traps (Nit), polarization types, and organic interlayers at low frequencies. The observed anomalous peak in the ε′ and ε″ versus voltage curves in the depletion zone is the result of re-structure/re-ordering molecules in these traps under voltage/electric-field, and Nit measured frequency (f = 1/T). As a result, the ε′ and ε″ will be given an excess value to their real-value at lower frequencies. Because Nit and dipoles do not have enough time to spin themselves in the direction of the electric field and follow the ac signal at high frequencies, they cannot contribute the true value of them. In general, series resistance (Rs) and the interfacial layer are effective in the accumulation zone, while Nit is effective in the depletion region. These findings demonstrate that pure and (Gr:PVA) polymer-films at the M/S interface can be employed successfully in place of standard oxide materials. According to the comparison of dielectric constants, electrical modulus, impedance, and ac conductivity of all three structures at 100 kHz and 1 MHz frequencies, 3% Gr doping to PVA increases interfacial characteristics.

Biosurfactants—An Overview

AbstractThe large structural and functional variety of bio‐surfactants (BS), which are produced by microorganisms, leads to the use of several methods to study these amphiphilic molecules. This review seeks to consolidate information on various surface‐active product extraction techniques, microbiological screening methodologies, and analytical terminologies utilized in this sector. The potential benefits and drawbacks of various approaches for studying cell biomass or microbial culture broth for the generation of surface‐reactive chemicals are also discussed. Additionally, the most popular techniques for detection, structural characterization, and purification of a variety of BS are introduced. A number of straightforward techniques are described in detail, including dialysis, ion exchange, solvent extraction, ultrafiltration, lyophilization, and thin layer chromatography (TLC). In addition to more sophisticated techniques like nuclear magnetic resonance (NMR), fast atom bombardment mass spectroscopy (FAB‐MS), gas chromatography‐mass spectroscopy (GC‐MS), high‐pressure liquid chromatography (HPLC), and infrared (IR), proteolysis and sequencing of amino acid are also explained. In this field of study, it is quite necessary to combine several analytical techniques, and it often takes multiple iterations to purify, isolate, and characterize different surface‐active substances. The numerous approaches that are essential for researching bio‐surfactants are covered in this review.

Smectite-bitumen interactions in non-aqueous bitumen extraction process

The non-aqueous extraction (NAE) is an alternative to the commercial water-based extraction technology used to liberate bitumen from oil sands. Although the impact of kaolinite, illite, chlorite, illite-smectite and montmorillonite on NAE process has been previously studied, the effect of different types of smectites has not been fully understood yet. In this work, mixtures of bitumen with bentonites dominated by saponite, hectorite, nontronite, beidellite and montmorillonite were reacted for several days and then washed with solvent (cyclohexane) to remove bitumen from the bentonites. The main goal was to better understand the impact of different smectites properties (specific surface area, pore structure characteristics, particle size, crystallite thickness, swelling ability, cation exchange capacity, layer charge and crystal-chemistry of smectites) on NAE process. The results showed that the porosity, particle size and swelling ability were the key parameters affecting the solvent-based bitumen recovery under the studied conditions. Samples with larger initial total pore volume and smaller particle size displayed reduced solvent bitumen extractability. The particle size of studied samples was affected primarily by swelling of smectites during the solvent bitumen extraction experiments. Smectites were swelling in water but not in cyclohexane. Swelling of smectite caused splitting of larger clay particles into many smaller particles. As a consequence, the efficiency of solvent bitumen extraction was significantly lower for fine grained samples, consisting of thin delaminated smectite particles, in which the bitumen was distributed among small-sized clay particles.

Enhanced Performance of All‐Inorganic Lead Halide Perovskite/MoS2 Heterojunction Photodetectors by Achieving Interfacial Carrier Separation

A heterojunction interface engineering aimed at improving the performance of all‐inorganic lead halide perovskite photodetectors (PDs) is demonstrated by coupling the two‐dimensional (2D) MoS2 materials with CsPbBr3 used in the chemical vapor deposition method in situ‐grown. The MoS2 carrier extraction layer facilitates electron injection, while the large injection barrier of the CsPbBr3/MoS2 heterojunction depletion layer keeps holes in the perovskite layer, resulting in effective separation of photogenerated carriers at the heterojunction interface. Moreover, the photoluminescence quenching and lifetime shortening of the heterojunction further prove that there is a large amount of charge transfer between the CsPbBr3 and MoS2 interface. As a result, PDs based on the CsPbBr3/MoS2/interdigitated array electrodes (IDA) heterojunction exhibit remarkable performance, such as high photoresponsivity (23.4 A W−1), detectivity (1.48 × 1013 Jones), and switching ratio (1.35 × 105), all of which are an order of magnitude better than pure CsPbBr3 PDs. The heterojunction PD also presents a superior response time (0.07 ms).

Enhancement and Broadening of the Internal Electric Field of Hole-Transport-Layer-Free Perovskite Solar Cells by Quantum Dot Interface Modification.

Hole-transport-layer-free perovskite solar cells have attracted strong interest due to their simple structure and low cost, but charge recombination is serious. Built-in electric field engineering is an intrinsic driver to facilitate charge separation transport and improve the efficiency of photovoltaic devices. However, the enhancement of the built-in electric field strength is often accompanied by the narrowing of the space charge region, which becomes a key constraint to the performance improvement of the device. Here, we propose an effective regulation method, the component engineering of quantum dots, to enhance the strength of the built-in electric field and broaden the range of space charge. By using all inorganic CsPbBrxI3-x (x = 0, 1, 2, 3) quantum dot interface modification to passivate the defects of MAPbI3 perovskite films, the regulation law of quantum dot components on the work function of perovskite films was revealed, and the mechanism of their influence on the internal electric field intensity and space charge region distribution was further clarified, thereby fundamentally solving the serious problem of charge recombination. As directly observed by electron-beam-induced current (EBIC), the introduction of CsPbBr2I quantum dots can effectively enhance the interfacial electric field intensity, widening the space charge region from 160 to 430 nm. Moreover, the efficiency of the hole-free transport layer perovskite solar cells modified by CsPbBr2I quantum dots was also significantly enhanced by 1.5 times. This is an important guideline for electric field modulation and efficiency improvement within photovoltaic devices with other simplified structures.

Modulating positive charge sites generations and iron oxidation state transitions in FeP4/CoP/C p-n heterojunction toward efficient oxygen evolution

Promoting the formation of positive charge active sites and high oxidation state FeOOH in the heterojunction electrocatalyst can enhance its intrinsic activity for oxygen evolution reaction (OER). However, the current synthesis methods that can simultaneously achieve both properties remain a great challenge. In this work, a feasible strategy for concurrently promoting the generation of positive charge active sites and high oxidation state metal species by constructing a heterojunction between FeP4 and CoP is proposed. Specifically, the p-n heterojunction between FeP4 and CoP is constructed by pyrolysis of MIL88A@FeCoLDH prepared by introducing Co through cation exchange using MIL88A as a template. The experimental and density functional theory calculation analyses suggest the construction of p-n heterojunction can effectively modulate the electron structure, optimize the d-band center, induce the generation of strong space charge region, and shorten the bond length of Fe-O, thus promoting the formation of positive charge active sites and high active species FeOOH and the adsorption ability of oxygen-containing intermediates for enhancing the OER performance. Benefiting from the synergistic effect between positive charge active sites and FeOOH, the obtained FeP4/CoP/C electrocatalyst exhibits a low overpotential of 258 mV for the OER at a current density of 10 mA cm−2 and superior stability at 20 mA cm−2 for 52 h. This work gives insights into the charge regulation effect in the heterojunction for enhancing the OER catalytic activity and provides a general strategy for designing more efficient oxygen evolution electrocatalysts.

Cross-sectional profile of photocarrier mobility in thin-film solar cells via multimolecular recombination and charge extraction by linearly increasing voltage (cs-p-CELIV)

The ability to spatially resolve the carrier mobility profile along the cross section of micrometer-thin solar cells is vital, both for fundamental studies in photovoltaics and as quality control for reproducibly obtaining high conversion efficiencies in commercial solar cell modules. Presently, no technique capable of such an endeavor is available to the best of our knowledge. Here, we introduce a novel method capable of profiling the carrier mobility along the z axis in thin-film photovoltaics. Our setup is based on the integration of photogenerated charge extraction by linearly increasing voltage (p-CELIV) with a scanning confocal optical microscope (SCOM) toward a confocal and cross-sectional p-CELIV (cs-p-CELIV) system. As monomolecular recombination of excess carriers is the most frequent radiative pathway for electrons and holes in solar cells at low power density of illumination, while multimolecular recombination dominates at high power, enhanced multimolecular recombination occurs at the SCOM focal plane. Thus, the cs-p-CELIV signal provides enhanced information on the mobility of all of the cross-sectional layers except the focal plane. By scanning the focal plane along the z axis, the mobility profile can be derived. To demonstrate our technique, we use it to investigate the carrier mobility in three hydrogenated amorphous silicon (a-Si:H) solar cells. The mobility profiles obtained by cs-p-CELIV correlate well with well-known depletion layer effects and the H content profile in a-Si:H, which is measured independently. Our findings are in excellent agreement with models suggesting a critical role of Si–H bonding in locally determining the carrier mobility in a-Si:H.

Theoretical analysis of doping of perovskite light-absorbing layer for highly efficient perovskite solar cells

The physical properties of perovskites—the central components of perovskite solar cells (PSCs)—are crucial for photovoltaic (PV) performance. Suitable doping of perovskites can improve the electric-field distribution within them, thus enhancing their PV performance. In this study, the effects of the three doping strategies on PV performance of MAPbI3 based PSCs were explored. First, uniform acceptor doping of perovskite was performed. With increasing uniform acceptor doping concentration (NA), the open-circuit voltage (VOC) gradually increased, but the short-circuit current density (JSC) decreased. As the decline in JSC limited further PCE increase, non-uniform acceptor doping of perovskite was performed, which increased the width of the space-charge region near the MAPbI3/SnO2 interface, promoting the flow of holes from MAPbI3 to the carbon electrode. The JSC increased from 19.05 to 22.30 mA cm−2, and the power conversion efficiency (PCE) increased from 19.74 % to 22.72 % when the doping concentration curve for non-uniform acceptor doping was a line passing through 3 × 1018 and 3 × 1014. In order to further enhance the PCE, simultaneous non-uniform acceptor doping and uniform donor doping of perovskite was adopted, which further improved the JSC and fill factor (FF), and the PCE increased from 22.72 % to 23.92 % when the uniform donor doping concentration was 1 × 1018 cm−3. This work provides a strategy of doping of perovskite for highly efficient PSCs.

Enhanced room temperature ethanol sensing: Insights into ZnSnVO nanocomposites catalytic behavior and electron transport

In the present investigations, zinc oxide, tin oxide, vanadium oxide - ternary combinations (ZnSnVO) prepared by hydrothermal route were characterized using the state-of-the-art facilities and were systematically analyzed. The interface properties between the grain and grain boundaries of the oxides were studied using Conductive atomic force microscopic (CAFM) studies. From the detailed investigations on topography and I-V characteristics, it is revealed that, zinc-tin-vanadium oxide nanocomposite with smaller barrier height of 0.189 eV exhibited pronounced response magnitude of 98.96 % at a faster rate of 32 s at room temperature. The enhanced ethanol sensing property of the ternary nanocomposite is attributed to the hierarchical morphology with large surface area, the formation of heterojunction at the interface, tuning the schottky barrier height, depletion layer manipulation and the electronic effects.

Electron irradiation-induced elements depletion and macroscopic changes in ternary borosilicate glasses: Mechanism and composition dependence

Glass, utilized for immobilizing high-level radioactive waste, experiences a decrease in mechanical properties and an increased risk of radioactive release after being exposed to β-radiation. A series of ternary borosilicate glasses were irradiated with 10 MeV electrons to doses ranging from 1 × 104 to 1 × 107 Gy. Nano-indentation, X-ray photoelectron spectroscopy, Time-of-Flight secondary ion mass spectrometry and Fourier-Transform infrared spectroscopy were used to characterize the glasses. After irradiation, the hardness of the glass decreased dramatically; the depletion of sodium, boron, oxygen and the enrichment of hydrogen, carbon in the glass surface were observed. The diffusion coefficients and depletion depths at different doses were fitted, both related to the composition of glass. With the absorbed dose increasing, Q0 ∼ Q2 transformed to Q3 and Q4, BO3 and BO4 decreased, molecular water and hydroxyl appeared. The formation of the depletion zone caused the reduction in hardness induced by irradiation. The glass showed phase separation characteristics. The mechanism and detailed process of element depletion were discussed. The composition dependence of depletion was explained based on the energy barrier model. The diffusion coefficient of elements depends on the activation energy of alkali.