Donor Defects Research Articles

The role of native point defects and donor impurities in the electrical properties of ZnSb2O4: a hybrid density-functional study.

The ceramic material zinc antimony oxide ZnSb2O4 has promising electrical and magnetic properties, making it suitable for various applications such as electrochemical and energy storage. However, the effects of point defects and impurities on its electrical properties have never been revealed. Here, we employ hybrid density-functional calculations to investigate the energetics and electronic properties of native point defects and donor impurities in ZnSb2O4. The energetically favorable configurations of native point defects under selected growth conditions (O-rich and O-poor) are identified based on the calculated formation energies. The study finds no shallow donor and shallow acceptor defects with low formation energies. Still, the oxygen vacancy (VO) has the lowest formation energy among the donor-type defects under O-rich and O-poor conditions. However, it acts as a very deep acceptor, making it unlikely to provide free electron carriers to the conduction band. Moreover, electron carriers are likely to be compensated by the formation of zinc vacancies (VZn) and the zinc substituted for antimony (ZnSb), which behave as dominant acceptors. Our analysis of the charge neutrality conditions estimates that the Fermi level of undoped ZnSb2O4 would be pinned in a range that is 2.60 eV to 3.12 eV above the VBM for O-rich to O-poor growth conditions, respectively, suggesting that this material is semi-insulating. The possibility of enhancing free electron carriers by doping with Al, Ga, In, and F impurities is also investigated. Our results, however, indicate that high n-type conductivity is hindered by self-compensation in which the impurities additionally act as electron killers. Our results suggest that other impurity candidates and approaches may need to be considered to efficiently dope this material into n-type. Overall, this work paves the way for point defect engineering in this class of ternary oxides.

Theoretical insights into the defect performance of the wide bandgap semiconductor BaS.

Wide bandgap semiconductors materials (WBGSMs) are of great interest for their applications in transparent electronics and power electronics. Recent studies have shown that BaS is a potential transparent conducting material but the knowledge of it is deficient. Herein, we systemically investigate its electronic structure and evaluate the effects of its intrinsic defects and extrinsic dopants by utilizing the hybrid density functional method. The obtained results show that BaS is an indirect bandgap semiconductor with a bandgap of 3.88 eV. Its electron-effective mass is very small (0.33 m0). We find that the intrinsic n-type conductivity of BaS is connected with the shallow donor defect sulfur vacancy (VS). Regarding extrinsic dopants (group IA atoms), we find that Li and Na are favorable n-type dopants, while K and Rb are p-type dopants. Among these impurities, the Li interstitial (Liint) configuration possesses the lowest formation energy of 0.114 eV. Based on thermodynamic simulations, we find that the electron density can reach 2.39 × 1020 cm-3 in Li-doped BaS at room temperature, which is comparable to those of typical WBGSMs In2O3, BaSnO3, and β-Ga2O3. We expect BaS could replace typical WBGSMs in some applications. Moreover, its component elements Ba and S are non-toxic, cheap, and earth-abundant, making it a very competitive candidate for WBGSMs. Based on these results, we deem BaS a promising candidate for optoelectronic applications.

Realistic Multidimensional Optoelectrical Modeling Guide for Copper Indium Gallium Diselenide Solar Cells

Herein, an optoelectrical model is presented for copper indium gallium diselenide (CIGSe) solar cells in COMSOL Multiphysics, capable of multidimensional simulations, and it is applied to ultrathin (500 nm absorber thickness) solar cells. First, the modeling approach is shown. Special attention is paid to back contact materials, interface states, and defect application and their impact on the current–voltage (J–V) characteristics. To address whether the back contact is Schottky or Ohmic, the influence of the Schottky barrier height, recombination velocity, and interface states is shown. Then, the additional application of an acceptor defect gradient at the absorber back and a donor defect density distribution at the p–n junction is investigated. The results of these parameter adjustments are discussed, and the trends are shown to enable fast fitting of experimental J–V curves. Finally, the results are compared to the experimental J–V curves for indium tin oxide and Mo back contact, and challenges encountered are discussed while fitting. The optoelectrical model for CIGSe solar cells, established in two dimensions here, paves the way for comprehensively describing 2D and 3D solar cell structures, e.g., nanotextured or microsolar cells, as well as for considering different absorber thicknesses.

24% Efficient, Simple ZnSe/Sb2Se3 Heterojunction Solar Cell: An Analysis of PV Characteristics and Defects.

In this work, a new wide-band-gap n-type buffer layer, ZnSe, has been proposed and investigated for an antimony selenide (Sb2Se3)-based thin-film solar cell. The study aims to boost the Sb2Se3-based solar cell's performance by incorporating a cheap, widely accessible ZnSe buffer layer into the solar cell structure as a replacement for the CdS layer. Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D) simulation software is used to thoroughly analyze the photovoltaic parameters of the heterojunction structure ZnSe/Sb2Se3. It includes open circuit voltage (V OC), short-circuit current density (J SC), fill factor (FF), power conversion efficiency (PCE), and external quantum efficiency (EQE). The absorber layer (Sb2Se3) thickness is adjusted from 0.5 to 3.0 μm to perfect the device. In addition, the influence of cell resistances, radiative recombination coefficient, acceptor and donor defect concentration in the Sb2Se3 layer, and interface defects of the ZnSe/Sb2Se3 layer on overall device performance are investigated. The ZnSe buffer layer and the Sb2Se3 absorber layer are designed to have optimal thicknesses of 100 nm and 1.5 μm, respectively. The proposed device's efficiency with optimized parameters is calculated to be 24%. According to the simulation results, it is possible to build Sb2Se3-based thin-film solar devices at a low cost and with high efficiency by incorporating ZnSe as an electron transport layer.

Highly Efficient Flexible Perovskite Solar Cells through Pentylammonium Acetate Modification with Certified Efficiency of 23.35.

Among the emerging photovoltaic technologies, rigid perovskite solar cells (PSCs) have made tremendous development owing to their exceptional power conversion efficiency (PCE) of up to25.7%. However, the record PCE of flexible PSCs (≈22.4%) still lags far behind their rigid counterparts and their mechanical stabilities are also not satisfactory. Herein, through modifying the interface between perovskite and hole transport layer via pentylammonium acetate (PenAAc) molecule a highly efficient and stable flexible inverted PSC is reported. Through synthetic manipulation of anion and cation, it is shown that the PenA+ and Ac- have strong chemical binding with both acceptor and donor defects of surface-terminating ends on perovskite films. The PenAAc-modified flexible PSCs achieve a record PCE of23.68% (0.08 cm2 , certified: 23.35%) with a high open-circuit voltage (VOC ) of1.17V. Large-area devices (1.0 cm2 ) also realized an exceptional PCE of21.52%. Moreover, the fabricated devices show excellent stability under mechanical bending, with PCE remaining above91% of the original PCE even after5000 bends.

Is the polarity of the Co3O4(111) surface compensated by electron transfer from bulk donor defects?

Experimental studies have shown that the Co3O4(111) surface exists as an unreconstructed (1 × 1) truncated bulk termination. Polarity compensation of this polar surface thus has to occur by a transfer of electrons, which creates partially occupied valence states and makes the surface metallic. Here we show by Hubbard-U corrected density-functional theory calculations that such a polarity compensation mechanism would make the surface highly reactive, which is not in agreement with experimental observations. An additional compensation mechanism has to be at work, by which the partially occupied valence band states are filled by electrons without requiring a reconstruction of the surface. As such an mechanism we propose the transfer of electrons from bulk donor defects to the surface. By employing this mechanism in our calculations we recover the experimentally observed reactivity. This demonstrates that for all polar surfaces, which are fully or partially polarity compensated by the transfer of electrons, additional electronic effects have to be considered in any electronic structure calculation in order to capture the correct surface chemistry.

First-principle study on the effect of S/Se/Te doping and VZn-Hi coexistence on ZnO electrical conductivity

Abstract In a vacuum environment, when ZnO is prepared using the chemical vapor deposition method and the molecular beam epitaxial growth method, H-gap impurities inevitably remain in the ZnO system, which is often ignored. The study of Zn vacancies under experimental conditions poses a challenge. Second, as an n-type semiconductor, ZnO is characterized by a self-compensation of natural donor defects and poor stability, which severely limit the acquisition of p-type ZnO. Based on the above problems, the conductive properties of S/Se/Te doped and VZn-Hi coexisting ZnO were investigated by first principle to acquire high-stability and high-quality p-ZnO. The study found that Zn35SO35, Zn35SeO35, and Zn35SHiO35 all have good p-type conductivity, which can effectively improve hole mobility and electrical conductivity. Among them, Zn35SO35 has the largest hole concentration at 2.80×1021 cm−3, as well as the best conductivity. The choice of Zn35SO35 provides a reference for obtaining new high-quality p-type ZnO semiconductors.

Comparison of reading man flap and skin grafting for closure of resultant donor defects in homodigital reverse flow flaps

The reading man procedure is a valuable treatment option for circular defects of different parts of the body. The aim of this study was to compare reading man procedure and skin grafting for coverage of resultant donor defects in homodigital reverse flow flaps. From January 2018 to October 2020, 38 patients underwent fingertip reconstruction using homodigital reverse flow flaps. The donor sites were resurfaced with full-thickness skin grafts in 20 patients and with reading man flaps in 18 patients. Flap survival, postoperative complications, operative time for closure of donor site, return work time, range of motion of the injured fingers, static two-point discrimination, and aesthetic results were evaluated. All the outcomes, including flap survival, postoperative complications, operative time for closure of donor site, return work time, range of motion of the injured fingers, static two-point discrimination, and aesthetic results, were similar between the two groups. No patients complained of cold intolerance or hypersensitivity. The reading man flap is useful and reliable for covering resultant donor defects in homodigital reverse flow flaps. The functional and aesthetic outcomes in both groups are similar.

A Class of Auxiliary Passivators for Polymer Dielectrics

AbstractHigh‐electrical‐strength polymer dielectrics are essential for advanced devices with high power and/or high integration densities and film capacitors with high energy‐storage densities. Key factors affecting the polymer dielectric electrical strength are deep‐level defect states, which lead to electron and hole accumulation. Numerous deep‐level defect states lead to charge accumulation in the polymer dielectric during operation, contributing to local electric field distortion and resulting in flashover or breakdown. In this work, first‐principles calculations and experiments reveal that VH (i.e., H vacancies) in the polymer dielectric molecular chain can create defect states deep in the bandgap. RCl (R = Li, Na, K) can be used for passivating the deep‐level polymer dielectric defect states. In addition, the passivation mechanisms are analyzed. The RCl cations can passivate deep‐level defect states into shallow‐level acceptor defect states because the RCl dipole moment regulates the deep‐level defect state energy. The RCl anions can passivate deep‐level defect states into shallow‐level donor defect states by forming a stable covalent bond between carbon and lone‐pair electrons. This work supports the design of high‐electrical‐strength polymer dielectrics.

Effect of annealing in air on the microstructural and thermoelectric characteristics of ZnO-based ceramics synthesized in a reducing atmosphere

Sintering in a reducing atmosphere, in comparison with sintering in air, greatly improves the electrical performance of ZnO-based thermoelectric materials. However, it also raises a question concerning their chemical stability in air for applications at high temperatures. The influence of annealing in air at temperatures up to 1000°C on the characteristics of ZnO-based ceramics synthesized in a reducing atmosphere of N2 + H2 was studied. The annealing process primarily results in acceptor states at the grain boundaries with the formation of electrostatic Schottky barriers, leading to decreased charge-carrier mobility and a lowering of the electrical conductivity and consequently 4-times lower power factor in comparison with the ceramics before annealing. The annealing in air does not affect the enhanced solid solubility of the donor dopants (i.e., Al) in the ceramics by sintering in a reducing atmosphere; however, it lowers the concentration of intrinsic donor defects, i.e. zinc interstitials (Zni) and oxygen vacancies (VO), thus decreasing the concentration of charge carriers. Nevertheless, the power factor of air-annealed ceramics was still 8-times higher than for ZnO ceramics prepared only by sintering in air. These results provide guidelines for the development of ZnO ceramics with annealing in air at high temperatures up to 1000°C after sintering in a reducing atmosphere, which not only enhanced thermoelectric characteristics, but also improved stability for applications in air at high temperatures, compared to the samples synthesis in air only.

Understanding the Effect of Intrinsic Defects in Lead-Free Vacancy-Ordered Double Perovskites Cs2PdBr6

Vacancy-ordered double perovskites, the variant of metal-halide perovskites, have excellent potential for use in optoelectronic and thermoelectric devices. A narrow region of forming the stable vacancy-ordered double perovskite Cs2PdBr6 by the chemical potential calculation via the first principles method was reported. Perdew–Burke–Ernzerhof functionals were used to investigate the possible intrinsic defects and the corresponding formation energy of Cs2PdBr6. Under the Pd-rich condition, the VBr defect was spontaneously formed as it has the lowest formation energy among all donor defects. In contrast, the sample became a p-type conducting material with a high hole concentration under the Pd-poor condition. This indicates that the defect-induced decline of photoelectric properties of Cs2PdBr6 can be alleviated by regulating the VBr defect alone. Finally, the Cs2PdBr6 microcrystals were fabricated via hydrothermal synthesis. In addition, XRD, PL, and Raman spectroscopy were also performed on Cs2PdBr6 powder to characterize the microstructure and optical properties of the compound; the results showed that VBr defects can be formed spontaneously, which is consistent with our theoretical calculations.

Defect Pair Formation in FAPbI3 Perovskite Solar Cell Absorbers.

Formamidinium lead iodide (FAPbI3) based hybrid perovskite light absorbers have shown remarkable performance in recent years. Since they have unique set of optoelectronic characteristics, they are considered as a good candidate absorber material for future solar cell applications. Until recently, much research had focused on the quantitative analysis of point defects on halide-based perovskite solar cells. Studies show that understanding defect mechanisms in perovskites has a huge impact on efficiency and stability improvements; however, such mechanisms have not been fully understood yet. Here, using first-principles calculations, we investigate the possible defect pair formations in FAPbI3, characterized by their formation energies and charge transitions. We found that while some donor and acceptor point defects are unstable and shallow when they are isolated, they form stable and deep-trap defect pairs and potentially limit the optoelectronic performance. We anticipate that our results will influence future discussions on the impact of defect formation on the performance and stability of perovskite solar cells.

Quasiparticle self-consistent GW band structures and phase transitions of LiAlO2 in tetrahedrally and octahedrally coordinated structures

A first-principles computational study is presented of various phases of LiAlO$_2$.The $\beta$ and $\gamma$ tetrahedral phases are found to be very close in energy with the $\gamma$ phase having the lowest energy. The octahedral $\alpha$ phase is a high-pressure phase and the transition pressure from the $\gamma$ and $\beta$ phases to $\alpha$ is determined to be about 1 GPa. The electronic band structures are determined using the quasiparticle self-consistent (QS) $GW$ method. The effective masses of the band edges and the nature of the band gaps are presented. The lowest energy $\gamma$ phase is found to have a pseudodirect gap of 7.69 eV. The gap is direct at $\Gamma$ but corresponds to a dipole forbidden transition. The imaginary part of the dielectric function and the absorption coefficient are calculated in the long-wavelength limit and the random phase approximation, without local field or electron-hole interaction effects for each phase and their anisotropies are discussed. Si doping on the Al site is investigated as a possible $n$-type dopant in $\gamma$-LiAlO$_2$ using a 128 atom supercell corresponding to 3.125 \% Si on the Al sublattice in the generalized gradient approximation and a smaller 16 atom cell with 25 \% Si in the QS$GW$ approximation. The Si is found to significantly perturb the conduction band and lower the gap but a clearly separated deep donor defect level is not found. However, the donor binding energy is still expected to be relatively deep, of order a few 0.1 eV in the hydrogenic effective mass approximation.

Hidden impurities in transparent conducting oxides: study of vacancies-related defects and impurities in (Cu–Ni) co-doped ZnO films

The effect of hydrogen and nitrogen impurities on the physical properties of transparent conductive oxides is investigated in this study. Therefore, 5 wt.% of copper and 5 wt.% of nickel co-doped zinc oxide ((Cu–Ni)/ZnO) films were prepared using the sol–gel method. The (Cu–Ni)/ZnO films were annealed in an oven at 500 °C for 2 h under air, vacuum, nitrogen, and argon atmospheres. The synthesized zinc hydroxide film was transformed to zinc oxide film during the annealing by evaporating {mathrm{H}}_{2}mathrm{O}. Films annealed under the mentioned atmosphere including as-prepared one were characterized by analyzing with UV–Vis and FTIR spectra in addition to the 2D mapping electrical conductivity of the surface measured by the 4-point probe. The annealed films under air, vacuum, and argon atmospheres led to generate H-related impurities bounded to the oxygen vacancy ({mathrm{H}}_{mathrm{O}}) which they act as shallow donor defects resulting in forming (Cu–Ni)/ZnO films into n-type materials. Whereas, the film annealed under a nitrogen atmosphere has N-related defects bounding to the zinc vacancy ({mathrm{N}}_{mathrm{Zn}}) which they act as shallow acceptor defects resulting in transforming the film from n-type to p-type. These defects affect the optical, electrical, and optoelectronic properties of the (Cu–Ni)/ZnO films.

The SrS doped with Cl and K: a promising ambipolar semiconductor for transparent electronics application

Wide-gap semiconductors are essential for current optoelectronics due to the good conductivity and transparency. Although the significant successes have been achieved for n-type transparent conducting materials (TCMs), the p-type TCMs seriously lag behind the n-type counterparts, which severely hinder the developments of the high-performance transparent electronic devices. In present work, we predict the transparent ambipolar conducting can be obtained in SrS by utilizing the hybrid functional method. The Cl substituting S and K substituting Sr (labeled as ClS and KSr) are typical shallow donor and acceptor defects. Compared to conduction band minimum (valence band maximum), the ionization energies for ClS (KSr) would converge to 0.02 (0.14) eV. Using the equilibrium fabricate method, the free electrons (holes) density can reach 1.24 × 1019 cm−3 (1.23 × 1018 cm−3) at room temperature. The effective masses for electron and hole are 0.32 and 0.87 m 0 (m 0 is the mass of a free electron). In the visible light regions, the high transparency can be kept due to its weak inter-band and intra-band absorptions as well as the negligible plasmonic effect. High density of carriers, smaller effective mass and high transparency show SrS doped with Cl and K is a promising ambipolar transparent semiconductor. This work provides insights to realize the high performance ambipolar TCMs. Once the excellent ambipolar TCMs is explored, the high-performance transparent devices are expected in the future.

Investigation of ferromagnetism and dual donor defects in Y-doped ZnO thin films

We report here the room temperature ferromagnetism in Y-doped ZnO thin films grown by RF magnetron sputtering. XRD and Raman spectra analysis revealed that pristine and Y-doped ZnO thin films are crystallised in hexagonal wurtzite structure. XPS was performed to confirm the electronic states of elements present in the films. FESEM images of the films were recorded to study their morphological properties. EDAX analysis was also performed to confirm the presence of Y in ZnO thin films. The point defects in the samples were analysed using photoluminescence spectrometer and EPR spectrometer to understand the mechanism behind the magnetic properties exhibited. It is found that zinc interstitial (Zni +) and oxygen vacancy (VO +) defects coexist in the samples and help in setting ferromagnetic properties in Y-doped ZnO thin films. VSM analysis indicated that Y-doped ZnO thin films show ferromagnetic nature while the pure ZnO thin film exhibits diamagnetic behaviour. The dual donor defect (Zni + and VO +) assisted bound magnetic polaron model has been proposed to explain the Y-doped ZnO diluted magnetic semiconductor system. It has been observed that the results are more reliable and reproducible.

Electrospun ZnO/Pd Nanofibers as Extremely Sensitive Material for Hydrogen Detection in Oxygen Free Gas Phase.

The development of safety sensors is an urgent necessity for the successful use of hydrogen in real conditions, which may differ, in particular, by the oxygen content in the surrounding atmosphere. Palladium-modified zinc oxide shows the high sensitivity when detecting hydrogen in air; however, studies of the sensor properties and the operation mechanism of the ZnO/Pd sensor when reducing gases are detected in an oxygen deficient or inert atmosphere have not been effectuated. In this work, we synthesized the ZnO and ZnO/Pd nanofibers by electrospinning and for the first time determined their sensor properties in the detection of CO, NH3 and H2 in different oxygen backgrounds. The microstructure and composition of nanofibers were characterized by electron microscopy, X-ray diffraction, X-ray fluorescent spectroscopy, and X-ray photoelectron spectroscopy. The interaction with the gas phase was investigated in situ by diffuse reflectance IR Fourier transform spectroscopy (DRIFTS). The sensor properties of ZnO and ZnO/Pd nanofibers were studied at 100–450 °C towards CO, NH3 and H2 in the N2/O2 gas mixtures containing 0.0005–20% O2. When detecting CO, a decrease in the oxygen concentration from 20 to 0.0005% in the gas phase does not lead to a significant change in the sensor response. At the same time, when detecting NH3 and especially H2, a decrease in oxygen concentration down to 0.0005% results in the dramatic increase in the sensor response of ZnO/Pd nanofibers. This result is discussed in terms of palladium hydride formation, modulation of the potential barrier at the ZnO/Pd interface, as well as changes in the concentration of donor defects and charge carriers in the ZnO matrix. Synthesized electrospun ZnO/Pd nanofibers are extremely promising materials for sensors for detecting hydrogen in an oxygen free atmosphere.

Suppressing Charged Cation Antisites via Se Vapor Annealing Enables p-Type Dopability in AgBiSe2 -SnSe Thermoelectrics.

Cation disordering is commonly found in multinary cubic compounds, but its effect on electronic properties has been neglected because of difficulties in determining the ordered structure and defect energetics. An absence of rational understanding of the point defects present has led to poor reproducibility and uncontrolled conduction type. AgBiSe2 is a representative compound that suffers from poor reproducibility of thermoelectric properties, while the origins of its intrinsic n-type conductivity remain speculative. Here, it is demonstrated that cation disordering is facilitated by BiAg charged antisite defects in cubic AgBiSe2 which also act as a principal donor defect that greatly controls the electronic properties. Using density functional theory calculations and in situ Raman spectroscopy, how saturation annealing with selenium vapor can stabilize p-type conductivity in cubic AgBiSe2 alloyed with SnSe at high temperatures is elucidated. With stable and controlled hole concentration, a peak is observed in the weighted mobility and the density-of-states effective mass in AgBiSnSe3 , implying an increased valley degeneracy in this system. These findings corroborate the importance of considering the defect energetics for exploring the dopability of ternary thermoelectric chalcogenides and engineering electronic bands by controlling self-doping.

Unfolding the conductivity reversal n- to p-type in phosphorus-doped ZnO thin films by spin-on dopant (SOD) process

Phosphorus doping induced p-type doping in ZnO thin films based on spin-on dopant (SOD) process is reported in this article. Owing to the reduced dependence on the conventional amenities for diffusion/ion-implantation doping, the SOD process provides a simple and cheap doping method. The effect of SOD process temperature on conductivity ZnO thin films is investigated by altering the temperature from 700°C to 1000°C. Systematic field emission scanning electron microscopy analysis demonstrates the impact of doping temperature on the morphological properties of SOD. The x-ray diffraction measurements reveal that the p-type ZnO thin films had (002) preferred crystal orientation. At the same time, x-ray photoelectron spectroscopy validated the formation of the PZn–2VZn complex, which was responsible for the acceptor behaviour of films. Moreover, the photoluminescence spectra tracked down that the origin of 3.35 and 3.31 eV emission peaks is due to the acceptor bound exciton and free-electron to acceptor level transitions, respectively. Finally, an elevated hole concentration of 2.09 × 1016 cm−3 is achieved with a resistivity of 1.14 Ω-cm at 800°C doping temperature. However, the film doped at 900°C and 1000°C showed n-type behaviour due to the generation of high concentration donor defects. Here, we successfully demonstrate that the SOD process has great potential to produce high-quality p-type ZnO thin films suitable for optoelectronic devices applications.

Study of thermoelectric performance and intrinsic defect of promising n-type half-Heusler FeGeW

Half-Heusler (HH) compounds are considered promising thermoelectric materials for high-temperature power generation due to their good electrical properties and thermal stability. Some new HHs with excellent thermoelectric properties are found to be p-type, the discovery of competitive n-type HH materials has been extremely challenging. Here, we report a new HH compound FeGeW through first-principles calculation, which exhibits a high ZT of 2.36 at 1000 K. Systematically studied its thermoelectric performance indicates that a large dispersion or small band effective mass of conduction band can efficiently improve the electrical conductivity of n-type FeGeW. From the calculated formation energy of intrinsic point defects, we find that positive charged Fe interstitial are found to be the dominant defect at Fe-rich/Ge-poor condition, which account for the n-type conduction. Moreover the transition levels of Fe interstitial defect is shallow, which means that this donor defect does not damage electrical conductivity and thermoelectric performance. These results not only find a new n-type HH compound FeGeW, but also are helpful for understanding the roles of point defects in FeGeW, which is expected to encourage more experimental and theoretical investigations to study this kind of n-type HH thermoelectric material and seek out strategies to optimize thermoelectric performance using intrinsic point defect.