Deep Acceptor Level Research Articles

First-principles Study of the Impact of Hydrogen Passivation on the Charge State Transition Levels of the CiOi(Sii)n Defect Complexes in Silicon

Density functional theory (DFT) with the Heyd-Scuseria-Ernzerhof hybrid functional has been used to predict the stability, formation energy, geometric structure, and the charge state transition levels of the CiOi(Sii)n (i = interstitial) defect complex in silicon for n = 0, 1, 2. The effect of hydrogen passivation on the properties of the CiOi(Sii)n defect complex is also investigated. The results for the binding energies confirm the stability of the defect complexes at neutral charge state. The charge state transition levels show that CiOi induces a shallow donor level and a deep acceptor level. The CiOiSii and CiOi(Sii)2 however induced deep donor levels. After hydrogen passivation, the acceptor level of the CiOiSii and the CiOi(Sii)i defect complexes disappear and the donor levels for all the defect complexes move deeper in the band gap.

Chemical trend of a Cu impurity in Zn chalcogenides

Cu is usually considered as an effective dopant to introduce shallow acceptors in Zn chalcogenides because it is on the left-hand side of Zn in the Periodic Table. Here, using first-principles calculations based on the hybrid functional with spin polarization, we show that contrary to the common expectation, Cu substituting Zn ($\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$) in bulk Zn chalcogenides actually generates rather deep acceptor levels in ZnO, ZnS, and ZnSe, i.e., 2.91, 1.03, and 0.53 eV above the valence-band maximum (VBM), respectively, except in ZnTe (0.13 eV). More interestingly, the absolute Cu impurity energy level does not follow the variation of the VBM, decreasing from ZnTe to ZnSe to ZnS to ZnO, instead, it is the highest in ZnO. The abnormal behavior of $\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$ in ZnO is attributed to the fact that, due to the very low O $2p$-orbital energy, the $\mathrm{C}{\mathrm{u}}_{\mathrm{Zn}}$ defect wave function has dominantly localized the Cu $3d$-orbital component, whereas in other Zn chalcogenides, anion $p$ states are dominant. The localized Cu $3d$ state leads to the enhanced exchange energy that elevates the acceptor level, which explains why the Cu impurity level is abnormally deep in ZnO. This finding provides insight in designing shallow acceptor levels in II--VI semiconductors.

Raman and Photoluminescence Study of Al,N‐Codoped ZnO Films Deposited at Oxygen‐Rich Conditions by Magnetron Sputtering

Optical properties of as‐grown high nitrogen‐doped ZnO:Al,N films (with a variation of nitrogen concentration from 2.3 to 4.3 atomic %) are studied by Raman, photoluminescence, and Fourier‐transform infrared spectroscopy (FTIR). The intensity of mode A1LO, peaked at 580 cm−1, increases with increasing nitrogen concentration. The silent mode B1low at 275 cm−1 is clearly observed testifying increased disorder‐activated scattering in ZnO. Photoluminescence spectra reveal near‐band edge emission as well as several defect‐related bands, the intensity of which increases with nitrogen content. The blue band (2.61 eV) can be related to the transition from shallow donor level to deep nitrogen acceptor level. Also, incorporation of nitrogen in ZnO lattice causes appearance of both Zni and Oi defects responsible for violet (3.08 eV) and yellow (2.16 eV) emission band, respectively. At the same time near‐band edge emission of ZnO:Al,N films is not suppressed by simultaneously introduced Al and N impurities. Al compensates distortions in ZnO crystal lattice caused by nitrogen doping and, thus, stabilizes near‐band edge emission.

Understanding the effect of the carbon on the photovoltaic properties of the Cu2ZnSnS4

In this work, crystalline structure, formation energy, electronic, optical and current-voltage properties of Cu2ZnSnS4 (CZTS) with the presence of carbon (C) impurity at various sites is studied using the first-principles density functional theory (DFT) based on the generalized gradient approximation (GGA). Here, we considered possible four substitutional configurations of carbon doped CZTS supercells: Cu by C (Ccu), Cu by Zn (Czn), Sn by C (Csn) and S by C (CS). It was found that the presence of C leads to the formation of localized polarons which have dual functionality; (i) cause an increase in the scattering-limited mobility which reduces the transport efficiency, (ii) create deep acceptor level which acts as a recombination center allowing the scattering of the generated charges carriers. An enhancement in the photo-absorption is observed due to an increase in the density of states at the valence bands after the incorporation of C. This results in the efficiency enhancement by 8%. In addition, the presence of C reduces the transport efficiency and improves the photogeneration efficiency of CZTS in solar cell applications.

Point defects in Ga2O3

In the field of high-power electronics, gallium oxide (Ga2O3) is attracting attention due to its wide bandgap and ability to be doped n-type. Point defects, including vacancies, impurities, and dopants, play important roles in optimizing device performance. This tutorial discusses the fundamental properties of point defects in monoclinic β-Ga2O3 and the methods employed to study them. Oxygen vacancies are deep donors that do not cause n-type conductivity but may compensate acceptors. Gallium vacancies are deep acceptors that can be partially passivated by hydrogen. Substitutional magnesium is a promising acceptor that produces a semi-insulating material and also forms a complex with hydrogen. Calcium and iron also have deep acceptor levels. Iridium deep donors are introduced into crystals grown from a melt in an Ir crucible. Other defects are introduced by irradiation with energetic particles such as neutrons or protons. In addition to altering the electronic properties, defects give rise to UV/visible emission bands in photoluminescence and cathodoluminescence spectra.

Candidates for p-type doping of ZnGeN2

Various candidates for p-type doping in ZnGeN2 are considered and computationally studied using first-principles calculations. First, a brief update is made on our previous work about self-doping by deviations from stoichiometry, in the form of ZnGe, and Ga doping, GaGe. Both of these are hindered by competing donors in the form of GeZn and GaZn. We also consider Al instead of Ga doping. Cu would form an acceptor on both Zn and Ge sites. We determine the site-preference and consider also interstitial Cui. We find that CuZn, which is the preferred site, has a too deep level in the gap above the valence band maximum to be a useful p-type dopant. For C, we consider the CN acceptor as well as competing sites, inert CGe, and the Ci donor. We find that Ci forms a split-interstitial configuration and CGe is energetically close to CN, but the main conclusion is that the latter has a deep acceptor level unsuitable for p-type doping. Finally, we consider alkali metal doping. The LiGa defect is found to have the most favorable acceptor level position among the defects studied here, but it will suffer from possible compensation by Lii. Na and K are found to give deeper levels.

Interfacial Charge Dynamics in Metal-Oxide–Semiconductor Structures: The Effect of Deep Traps and Acceptor Levels in GaN

Using numerical simulations, we investigate the effects of deep traps and deep acceptor levels in magnesium-doped $\mathrm{Ga}\mathrm{N}$ on interface charges in the semiconductor-oxide interface. Specifically, in this work we address two open issues observed in experimental studies on $\mathrm{Ga}\mathrm{N}$ trench metal-oxide-semiconductor field-effect transistors. (i) We investigate the observed clockwise hysteresis in the transfer characteristics and elucidate the underlying physical mechanism causing it. By employing appropriate models for substitutional carbon at nitrogen sites (${C}_{N}$) and nitrogen vacancies (${V}_{N}$), we calculate the hysteresis dependence on the trap concentrations and the measurement sweep duration ${T}_{s}$. We show that ${C}_{N}$ acceptor traps in $p$-$\mathrm{Ga}\mathrm{N}$ are likely responsible for this phenomenon and the largest hysteresis is predicted for a sweep duration of ${T}_{s}\ensuremath{\approx}30\phantom{\rule{0.2em}{0ex}}\mathrm{s}$. (ii) We also address the apparent inconsistency between the experimental and theoretically predicted magnesium-ionization levels and the variations of the measured transfer characteristics, specifically the threshold voltage. We show that the bands bending in the channel area creates a layer in which magnesium is completely ionized. As a result, the magnesium partial ionization does not have an effect and, while the threshold voltage decreases, nor does the breakdown voltage, as observed experimentally. The measured threshold voltage, which is lower than the theoretically predicted value, is caused by fixed and trapped charges at the interface, in agreement with values reported in the literature.

Influence of high-temperature annealing on the characteristics of fast electron-irradiated p-n-structures based on neutron doped silicon

The investigation results of the annealing influence (Тann = 300–800 ºС) on the minority charge currier lifetime tP in the n-base of p-n-structures, manufactured on the base of neutron transmutation doped silicon (NTD) КОФ300, irradiated at room temperature by different fluences (F = 1 · 1014 – 3 · 1016 cm–2) of electrons with the energy of Еe = 4 MeV are presented. It is established that at low electron fluences (F = 1 · 1014 cm–2), the annealing of minority charge currier lifetime tP in the n-base of p-n-structures occurs in two stages: the first – 320–400 ºС and the second – 550–650 ºС. At higher electron fluences (F = 5 · 1015–2 · 1016 cm–2), three annealing stages occur: the first – 400–450 ºС, the second – 520–650 ºС and the third – 710–770 ºС. At this, the structure barrier capacitance C dependences on Тann at high electron fluences show the geometry capacitance up to the annealing temperatures Тann = 400 ºС. In the annealing temperature range of Тann = 420–570 ºС, the increase in С with maximum is seen at Тann = 480 ºС and a subsequent decrease in the geometry capacitance is seen in the annealing temperature range of Тann = 600–670 ºС, and then again the increase in С occurs in the annealing temperature range of Тann = 720–770 ºС reaching the С values corresponding to those of the non-irradiated samples in the annealing temperature range of Тann = 770–800 ºС. The analysis of the DLTS-spectra of the investigated structures has allowed establishing the formation in the annealing process of the deep acceptor level ЕС – 0.68 eV at Тann > 400 ºС, the deep donor level ЕС – 0.32 eV in the annealing temperature range of Тann = 420–570 ºС and the deep acceptor level ЕС – 0.53 eV at Тann > 700 ºС, which satisfactorily explains the dependences of t P and С on Тann obtained in this paper.

Improvement of luminescence properties of n-GaN using TEGa precursor

Abstract The aim of this work is to compare and improve optical and structural properties of GaN layers prepared using TMGa or TEGa precursors. MOVPE grown GaN buffer layers on sapphire substrates are usually grown from TMGa precursor at the temperatures above 1000 °C. These layers contain deep and shallow acceptor levels which are responsible for blue and yellow defect bands in luminescent spectra. Both defect bands are detrimental for all major nitride device applications. Especially n-doped GaN layers suffer from strong yellow defect bands. In this work, it is shown that yellow band photoluminescence intensity can be suppressed by using TEGa precursor during the growth of n–doped GaN layers. Different kinds of growth parameters, such as growth temperature or growth rate, have been studied. It is also shown that the change of carrier gas (H2 or N2) has very strong influence on the layer quality. H2 carrier gas increased intensity of yellow band in sample grown from TEGa precursor while N2 carrier gas had the same effect for sample grown from TMGa precursor. Variable energy positron annihilation spectroscopy showed creation of single VGa in H2 atmosphere and clustering of VGa to big complexes ((VGa)3(VN)n) in N2 atmosphere.

Effects of Antimony- and Tin-Doping on the Mechanical Propertiesof Czochralski Silicon: Revealing the Role of Electrical Activity of Antimony

The mechanical properties of Czochralski (Cz) silicon wafers dictate fundamental limits on the fabrication of diverse electronic devices. Certain impurities with sufficiently high concentrations may affect the mechanical properties of Cz silicon. The underlying mechanisms for such influences have been being explored in the past decades. In this work, the effects of antimony (Sb)- and tin (Sn)-doping at 1018 cm−3 level on the mechanical properties of Czochralski (Cz) silicon have been comparatively investigated. Since Sb and Sn have quite close tetrahedral covalent radii in silicon, the lattice strains resulted from Sb- and Sn-doping and their consequent effects on the mechanical properties of silicon are approximately identical. In silicon, Sb is an electrically active impurity while Sn is a neutral one. Therefore, the present work can essentially reveal the role of electrical activity of Sb playing in the mechanical properties of Cz silicon. It is found that Sb-doped Cz (Sb-Cz) silicon possesses a slightly higher hardness than Sn-doped Cz (Sn-Cz) silicon. Moreover, the dislocation gliding at 500 or 600 °C in Sb-Cz silicon requires a much larger critical resolved shear stress than that in Sn-Cz silicon. At such two temperatures, Sb-Cz silicon remains to be n-type in electrical conduction. The aforementioned two results are believed to be ascribed to the resistance of dislocation motion by the Coulomb interaction between the positively charged Sb ions and the dislocations that are deep-level acceptors thus being negatively charged in Sb-Cz silicon. As the temperature is increased to 700 °C and above, the dislocation gliding in Sb-Cz silicon is not substantially different from that in Sn-Cz silicon. At such elevated temperatures, Sb-Cz silicon becomes intrinsic in electrical conduction like Sn-Cz silicon. In this context, there is no Coulomb interaction between Sb ions and dislocations anymore to impede the dislocation gliding in Sb-Cz silicon. In addition, it is found that the indentation fracture toughness of Sb-Cz is almost the same as that of Sn-Cz silicon. Actually, the fracture of silicon is essentially a cleavage process, to which the electrical activity of Sb is irrelevant.

Minority carrier lifetime in indium doped silicon for photovoltaics

AbstractFor photovoltaics, switching the p‐type dopant in silicon wafers from boron to indium may be advantageous as boron plays an important role in the light‐induced degradation mechanism. With the continuous Czochralski crystal growth process it is now possible to produce indium doped silicon substrates with the required doping levels for solar cells. This study aims to understand factors controlling the minority carrier lifetime in such substrates with a view to enabling the quantification of the possible benefits of indium doped material. Experiments are performed using temperature‐dependent Hall effect and injection‐dependent carrier lifetime measurements. The recombination rate is found to vary linearly with the concentration of un‐ionized indium which exists in the sample at room temperature due to indium's relatively deep acceptor level at 0.15 eV from the valence band. Lifetime in indium doped silicon is also shown to degrade rapidly under illumination, but to a level substantially higher than in equivalent boron doped silicon samples. A window of opportunity exists in which the minority carrier lifetime in degraded indium doped silicon is higher than the equivalent boron doped silicon, indicating it may be suitable as the base material for front contact photovoltaic cells.

High-Temperature Hall Effect Sensor Based on Epitaxial Graphene on High-Purity Semiinsulating 4H-SiC

In this report, we demonstrate a novel high-temperature Hall effect sensor that is based on quasi-free-standing monolayer graphene epitaxially grown on high-purity semiinsulating (SI) on-axis 4H-SiC(0001) substrate in a chemical vapor deposition process. To ensure statistical perspective, characteristics of 23 elements are determined as a function of temperature ranging from 300 to 770 K. Passivated with a 100-nm-thick atomic-layer-deposited aluminum oxide, the sensor offers current-mode sensitivity of 80 V/AT with thermal stability of -0.02%/K within the range between 300 and 573 K, and -0.06%/K between 573 and 770 K. The sensor's room-temperature output voltage is monitored in the magnetic field from -300 to +300 mT and its offset voltage at 0 T is assessed. Its high-temperature electrical properties are explained through a double-carrier transport involving spontaneous-polarization-induced holes in the graphene layer and thermally activated electrons emitted from a deep acceptor level related to silicon vacancy V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Si</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1-/2-</sup> occupying the k site of the 4H-SiC lattice. The sensor is compared with a previously reported one on vanadium-compensated SI on-axis 6H-SiC(0001). The new sensor's applicability to magnetic field detection at high temperatures is verified.

Radiation damage in p-type EPI silicon pad diodes irradiated with protons and neutrons

In view of the HL-LHC upgrade, radiation-tolerant silicon sensors containing low-resistivity p-type implants or substrates, like LGAD or HV-CMOS devices, are being developed in the framework of ATLAS, CMS, RD50 and other sensor R&D projects. These devices are facing a particular problem — the apparent deactivation of the doping due to the irradiation, the so-called acceptor removal effect. In the present work proton and neutron fluence-dependent radiation damage effects, including the change in leakage current and effective doping concentration, space charge sign-inversion, but also introduction and annealing of point- and cluster-like defects have been studied in Si pad diodes fabricated from p-type EPI material of different resistivity (10–1000 Ωcm). Standard electrical characterisations (IV, CV), TCT (Transient Current Technique) and TSC (Thermally Stimulated Current) techniques were applied. A correlation between effective doping concentration obtained from CV measurements and defect concentration Nt extracted from TSC measurements for both – neutron and proton – irradiations was observed pointing towards the microscopic origin of the acceptor removal. A detailed analysis of the dominant TSC peaks - E(30), BiOi and three main deep acceptor levels H(116), H(140) and H(152) - responsible for the changes in the effective space charge is performed. The origin and annealing behaviour of E(30) and H(40) and other cluster-related defects are discussed as well.

Structural, optical and Schottky diode properties of Cu2ZnSnS4 thin films grown by two-stage method

CZTS thin film was prepared by a two-stage process comprising sputter deposition of metallic Cu, Zn, and Sn layers followed annealing treatment of the metallic precursors in a sulfur atmosphere at 560 °C for 3 min. The CZTS thin film was investigated in the way of structural, optical and electrical properties. The XRD pattern of Cu-poor and Zn-rich CZTS thin film was dominated by characteristic peaks of kesterite CZTS planes. Raman spectra of the film ensured formation of kesterite CZTS phase and displayed formation of CTS and ZnS phases. Dense and polycrystalline surface features were observed in SEM images of CZTS thin film. Band–band transitions was not observed due to the probable concentration of deep acceptor levels in this material. The diode parameters of Mo/CZTS/Al structure such as ideality factor, barrier height and serial resistance were calculated employing temperature dependent I–V characteristics of Mo/CZTS/Al diode structure.

The structure and the optical-electrical properties of the ZnO films and the Al:ZnO/N: ZnO homojunction photodiode

In this article, Al or N-doped ZnO films are prepared by wet chemical deposition method, and then the Al-ZnO/N-ZnO homojunction photodiode is structured. The influence of triethanolamine (TEA) content and deposition temperature on the structure, phase, and optical-electrical properties of N-ZnO films is investigated. The results of X-ray Diffraction (XRD) measurement show that the N-ZnO films have a hexagonal wurtzite structure with a preferred growth orientation along (002) crystal plane. The obvious Raman peak appeared at 436 cm−1 should be assigned to non-polar high-frequency E2H mode, which indicates the good crystallinity of N-ZnO film. The results of low temperature photoluminescence (LT-PL) measurement exhibit that the peak of UV emission, which shifts from 386 to 390 nm with the increase in measurement temperature from 50 to 250 K, may be mainly the exciton emission, coming from shallow donor Zni to valence band (Zni →VB: ΔE~3.15 eV) or conduction band to the shallow acceptor No (CB→No: ΔE~3.215 eV). Two visible emissions peaks may be attributed to the electron transitions from the single charged oxygen vacancies Vo+ and the double charged oxygen vacancies Vo++ defects, respectively. Three infrared emission peaks may be related to the electron transitions from the transition from deep donor level (Vo, Zni) to deep acceptor level (OZn) or the intra band transition between two states of Vo and Zni. For the response times of Al-ZnO/N-ZnO homojunction photodiode, the rise time (τr) is <2 ms and the decay time (τd) is about 22 ms. The value of responsivity (R) is calculated to be about 0.274 mA/W.

Structural and optical properties of pulsed-laser deposited crystalline β-Ga2O3 thin films on silicon

Crystalline β-Ga2O3 thin films on (100)- and (111)-oriented Si substrates are produced by pulsed laser deposition. The as-deposited thin films are demonstrated to be polycrystalline and contain a slight deficit of oxygen atoms as measured by x-ray diffraction spectroscopy and Rutherford backscattering spectrometry, respectively. The crystallographic orientation of the Si substrate is found to play no role on the ultimate properties of the films. A direct optical band gap of 4.8 eV is determined by temperature-dependent photoluminescence excitation (PLE). Temperature-dependent PLE spectra reveal the existence of a deep acceptor level of around 1.1 eV with respect to the valence band related to self-trapped holes. We experimentally demonstrate that point defects in O-poor β-Ga2O3 thin films act as deep donors and the optical transitions are found to take place via recombination of electrons from one of the intrinsic deep donor levels with self-trapped holes located at 1.1 eV above the valence band. The 3.17 eV ultraviolet photoluminescence is proven to be related to self-trapped holes in a small polaron state between two O(II)-s sites, whereas the two blue (2.98, 2.72 eV) and the green (2.39 eV) luminescence bands are mainly originated from gallium-oxygen vacancy pairs in the (1-) charge state, gallium vacancies in the (2-) charge state and neutral oxygen interstitials, respectively.

Strategies for p-type doping of ZnGeN2

ZnGeN2 has been proposed as an attractive semiconductor for a number of applications, but doping is largely unexplored. We examine the behavior of Li, Cu, Al, Ga, In, and C as candidate acceptors using hybrid density functional theory. Cu, In, and C give rise to deep acceptor levels, but Li, Al, or Ga could potentially lead to p-type conductivity. Al is particularly attractive since it has an ionization energy of 0.24 eV, comparable to Mg in GaN. However, self-compensation due to wrong-site incorporation is a serious issue. We demonstrate that co-doping with hydrogen can be used to overcome this problem.

Surface doping of ZnO nanowires with Bi: Density-functional supercell calculations of defect energetics

Defect calculations using the density and hybrid functionals in combination with the supercell approach are employed to characterize the electrical properties of a number of ZnO nanowires of various thicknesses doped with Bi atoms occupying surface sites. The variation of the differences between the total energies of charged and neutral supercells with the supercell size is studied, which led the authors to devise an extrapolation procedure to obtain reliable defect energetics in the dilute defect limit. The calculated defect formation energies indicate that although the substitution of Bi into Zn or O sites can take place spontaneously under suitable thermodynamic conditions, the substitution into Zn sites is generally more likely. The defect (charge-state) transition energies are computed and parameterized as a function of the nanowire thickness. It is revealed that the substitution of Bi into O (Zn) sites on the surface of ZnO nanowires yields deep acceptor (shallow donor) levels (except for extremely thin nanowires). It is therefore concluded that the incorporation of Bi into the surface of ZnO nanowires results in $n$-type doping.

Effects of selenisation temperature on photoluminescence and photoluminescence excitation spectra of ZnO/CdS/Cu2ZnSnSe4/Mo/glass

The effect of solar cell processing (including etching in KCN along with deposition of CdS and ZnO) on photoluminescence (PL) spectra and bandgap Eg (measured at 4.2 K by photoluminescence excitation) of Cu2ZnSnSe4 films, produced by selenising metallic precursors at 450 °C, 500 °C and 550 °C, was studied. Temperature and excitation intensity analysis of the P1 dominant band in the PL spectra of solar cells suggests that after processing this band still can be assigned to the free-to-bound recombination of free electrons with holes bound at deep acceptor levels influenced by valence band-tails. However processing increased the intensity of P1 and blue shifted it. The strongest effect was observed for the film selenised at 500 °C. For the film selenised at 450 °C the blue shift and increase in the intensity were smaller and only a slight intensity rise was found for the film selenised at 550 °C. The intensity increase we assign to a reduction in the concentration of non-radiative recombination centers on the surface because of the etching and changes in doping due to inter-diffusion of Cd, S, Se and Zn after the deposition of CdS. Such an inter-diffusion depends on the elemental composition of the films defining the chemistry of defects and influencing Eg which increased in the film selenised at 500 °C but decreased in the other films. Processing increased the P1 shift rate (j-shift) with excitation power change in all the films demonstrating a higher compensation degree in the solar cells which is consistent with the formation of an interface layer containing new donors CdCu.

Uniform MoS2 nanolayer with sulfur vacancy on carbon nanotube networks as binder-free electrodes for asymmetrical supercapacitor

Molybdenum sulfide (MoS2) is regarded as a promising material for supercapacitor applications but the intrinsically low electrical conductivity greatly limits its high specific capacitances. Herein, we introduce sulfur vacancy on MoS2 nanolayer (MoS2−x) by a pulsed laser deposition (PLD) process. By further using the highly conductive carbon nanotube (CNT) networks as the current collector, the as-fabricated defect-rich MoS2@CNTs/Ni core/shell-structured electrode delivers an ultrahigh specific capacitance of 512F g−1 at 1 A g−1, excellent rate performance (342F g−1 at 30 A g−1) and long cycle life (no decay after 2000 cycles) in 1 M Na2SO4 electrolyte, which are among the best reported values for MoS2-based supercapacitors. Along with the experiment results, our DFT calculations further demonstrate that the S vacancy can create deep acceptor levels in the MoS2 monolayer, which can trap electrons and improve the electrons mobility. For practical application, we build an asymmetrical supercapacitor (ASC) with MoS2−x@CNTs/Ni as the positive electrode and CNT networks as the negative electrode, which exhibits a large energy density of 63 Wh kg−1 at 850 W kg−1 and an impressive power density of 25.5 kW kg−1 at 44.2 Wh kg−1. These results indicate that PLD is a very powerful technique to construct the binder-free film electrodes for energy storage applications.