High Density Of Free Carriers Research Articles

Building Conventional Metasurfaces with Unconventional Interband Plasmonics: A Versatile Route for Sustainable Structural Color Generation Based on Bismuth

AbstractPlasmonic metasurfaces for structural color generation are typically built using the archetypal noble metals, gold, and silver. These possess plasmonic properties in the visible spectrum due to their inherent high free carrier densities. However, they are much more expensive compared to many other metals and exhibit several nanofabrication issues such as bad surface adhesion or thermally activated inter‐diffusion. In this work, it is shown that interband plasmonic materials –whose optical properties are driven by interband transitions instead of free carriers— are appealing candidates for the fabrication of sustainable and cost‐efficient metasurfaces for structural coloring. By using bismuth, an environment‐friendly interband plasmonic material cheaper than gold and silver, nanodisks gap‐plasmon metasurfaces and planar Fabry‐Perot cavities are modeled and fabricated, which both successfully enable pure colors that can be robustly tailored upon suitable design. By direct experimental comparison between both types of design in terms of color efficiency, fabrication complexity, and angular robustness; how bismuth‐based gap surface plasmon metasurfaces can be excellent candidates for color microprinting is shown, whereas nanolayered Bi Fabry‐Pérot cavities are ideal for macroscopic color coatings due to their ease of fabrication and implementation.

Ultranarrow Mid-infrared Quantum Plasmon Resonance of Self-Doped Silver Selenide Nanocrystal.

The infrared quantum plasmon resonance (IR QPR) of nanocrystals (NCs) exhibits the combined properties of classical and quantum mechanics, potentially overcoming the limitations of conventional optical features. However, research on the development of localized surface plasmon resonance (LSPR) from colloidal quantum dots has stagnated, owing to the challenge of increasing the carrier density of semiconductor NCs. Herein, we present the mid-IR QPR of a self-doped Ag2Se NC with an exceptionally narrow bandwidth. Chemical modification of the NC surface with chloride realizes this narrow QPR bandwidth by achieving a high free-carrier density in the NC. The mid-IR QPR feature was thoroughly analyzed by using various experimental methods such as Fourier transform (FT) IR spectroscopy, X-ray photoelectron spectroscopy, and current-voltage measurements. In addition, the optical properties were theoretically analyzed using the plamon-in-a-box model and a modified hydrodynamic model that revealed the effect of coupling with the intraband transition and the limited nature of electron density in semiconductor NCs. Integrating the quantum effect into the plasmonic resonance reduces the peak bandwidth to 19.7 meV, which is an extremely narrow bandwidth compared with that of the LSPR of conventional metal oxide or metal chalcogenide NCs. Our results demonstrate that self-doped silver selenide quantum dots are excellent systems for studying mid-IR QPR.

Dynamics of Free Carrier Absorption and Refractive Index Dispersion in Si and Si/PolySi Microrings

We report pump-probe measurements of time resolved optical transmission spectra of Si and Si/poly-Si microrings after high free carrier densities have been generated by two-photon absorption of the pump pulse. From measurements, we can extract the recovery dynamics of free carrier absorption, refractive index dispersion, generated free carriers and finally the effective initial free carrier lifetimes. The method is validated by comparing modelling and simulations with measurements; the obtained results are in very good agreement with what predicted by the Shockley-Read-Hall recombination model for trap assisted recombination. We also propose a method for determining the empirical relations for free carrier absorption and refractive index dispersion in poly-Si waveguides.

Zr-doped indium oxide electrodes: Annealing and thickness effects on microstructure and carrier transport

Zr-doped indium oxide (In2O3:Zr) has been shown to satisfy the requirements of low resistance, wide band gap, and high infrared transmittance for application as a front contact in broadband solar cells. However, the reduction of indium usage in front of transparent electrodes is still an unsatisfied requirement. With the goal of reducing the amount of indium while leveraging its properties, in this work, In2O3:Zr films with reduced thickness compared to those standardly used in solar cells are studied. 100 to 15-nm-thick films were sputtered at room temperature and annealed in distinct atmospheres to study the links between thickness, microstructure, and optoelectronic properties. As-deposited films exhibit an amorphous microstructure embedding bixbyite In2O3 nanocrystals. Annealing in neutral (N2) or reducing atmosphere (H2) allows a slight growth of these crystallites but the layers remain mostly amorphous. Whereas annealing in air results in polycrystalline films with an average grain lateral size ranging from 350 to 500 nm. The large crystalline grains formed during air annealing lead to increased electron mobility for all thickness: up to 100cm2V-1s-1 for 100-nm-thick films and up to 50cm2V-1s-1 for 15-nm-thick films, which is remarkable for such thin polycrystalline films. Conversely, H2 annealing ensures high free-carrier densities (>1×1020cm-3) but not high mobilities, still achieving conductivities between 1000 and 2000Scm-1, with the films less than 50-nm-thick keeping high broadband transmittance. The possibility of thinning down In2O3:Zr to a few tens of nanometers while keeping both high lateral conductivity and good transparency makes this material a promising candidate to reduce the amount of indium in optoelectronic applications, such as flexible touch screens and solar cells.

Electronic properties and transformation kinetics of two prominent metastable defects introduced in GaAs during sputter deposition of Au Schottky contacts

Au Schottky barrier contacts (SBDs) were DC sputter deposited on Si doped n-type GaAs at a power of 150 W. Deep-level transient spectroscopy (DLTS) and Laplace DLTS were used to characterize the sputter-induced defects near the surface of the GaAs. In this study, I-V and C-V measurements showed that the sputter deposited diodes had a significantly lower barrier height and a higher free carrier density. Using DLTS, it was found that this sample contained seven defects – three of them were metastable while one of the others was highly dopant dependent. The energy levels of these defects are Ec – 0.046 eV, Ec – 0.22 eV, Ec – 0.30 eV, Ec – 0.55 eV, Ec – 0.56 eV, Ec – 0.83 eV and Ec – 0.84 eV. The EL2 defect was not observed in the sputtered samples, but one of the sputter-induced defects emitted in the same range as the EL2, however, it had two components and their DLTS signatures (Ec – 0.83 eV and Ec – 0.84 eV) differed significantly from that of the EL2. By applying different bias conditions (−2 V and zero V) for annealing procedures, the metastable defects (Ec – 0.30 eV and Ec – 0.56 eV) were transformed into each other. The pre-factor obtained from transformation rate of Ec – 0.56 eV →Ec – 0.30 eV under reverse bias was 3 × 1015 s−1 which is related to free carrier emission.

Investigation of structural and magnetic properties of Co+ ion implanted indium tin oxide thin films on polyethylene terephthalate (C10H8O4)n substrates by 100 keV ions

Indium Tin Oxide (ITO) thin films have been used extensively in many applications, such as solar cells. In particular, ITO has been the material of choice in flat panel displays as one of its electrodes due to its low resistivity, high transmission of visible light and high free carrier density that contributes to its relatively low electrical resistivity. Modification of ITO thin films on polymer substrates using transition metal ion beams is rarely reported in literature. In this work, ITO thin film samples were implanted with Co+ ions of energy 100 keV at fluences 1 × 1014, 1 × 1015 and 1 × 1016 ions/cm2. The grain sizes of the ITO thin films were observed to increase with increase in ion fluence, showing that the quality of the ITO thin films and crystallinity were getting enhanced. At a fluence of 1 × 1016 ions/cm2, a high value of 2.33 × 10−3 emu/g magnetization was estimated. The level of residual magnetism in the Co+ implanted thin films increased at an average of 35% with increase in ion fluence. This means that Co+ implanted ITO thin films have good ability to retain a certain amount of residual magnetic field at zero magnetizing, as the ion fluence increases. Furthermore, the Co+ ion implanted ITO thin films were found to exhibit clear room temperature ferromagnetism. The shift in hysteresis loops along applied magnetic field axes provides information about the exchange bias of Co+ ion implanted ITO thin films in relation to grain size.

Preparation and Photocatalytic Activities of Black TiO₂ in Vacuum and Ambient Temperature Environment.

The preparation conditions are important for the structure and properties of black TiO₂. In this paper, the black rutile TiO₂ with a particle size of approximately 5 nm was prepared in vacuum by the infrared nano-second laser sputtering deposition method. The study results indicated that the prepared black TiO₂ exhibited high light absorption from UV to near-infrared region. The lattice distortion and Ti3+ were responsible for the upward shift in the valance band, and the oxygen vacancy states were determined to be located about 0.7-1.18 eV under the conduction band, narrowing the band gap of TiO₂ from 3.2 eV to 2.1 eV. Although the black TiO₂ exhibited strong adsorption effects within the full spectrum and had a higher free carrier density, the presence of excess oxygen defects resulted in a higher recombination rate of the photo electron-hole pairs, which induced a poor photocatalytic performance of the black TiO₂. This work facilitates the understanding of the mechanisms mechanism of black TiO₂ formation via laser ablation, and emphasized the need for the controllability and quantification of oxygen vacancies.

Electrical Characteristics of Fluorine-Doped Zinc Oxynitride Thin-Film Transistors

Increasing demands for cost effective switching transistors in the flat panel display industry have led to the development of metal oxide semiconductors such as In-Ga-Zn-O (IGZO). Thin-film transistors (TFT) that incorporate such materials exhibit field effect mobility exceeding 10 cm2/Vs, and are suitable for the fabrication of large size liquid crystal display (LCD) panels with ultra-high definition (4000 ´ 2000 pixels). However, further advances in display technology aim at producing organic light-emitting diodes (OLEDs) that require relatively high driving currents. In this regard, devices with even higher field effect mobility (> 30 cm2/Vs) must be integrated in the backplane array. Recent studies of a relatively new type of semiconductor, zinc oxynitride (ZnON), have shown that high mobility semiconductor films can be obtained by reactively sputtering a Zn metal target, which involves a simple and inexpensive process. The optimization of the associated TFT properties usually consists of controlling the nitrogen to oxygen anion ratio or thermally annealing the ZnON layer, so as to obtain sufficiently low leakage current levels while preserving sufficiently high field effect mobility. It is usually reported that the nitrogen vacant sites (VNs) act as the major source of free electrons and carrier traps that may degrade the device properties over prolonged bias stress. In order to passivate such defects, fluorine doping were attempted in nitride semiconductors. The present work is a study on the effect of directly incorporating fluorine anions during the thin film growth, by co-sputtering a ZnF2 target alongside the Zn metal target. First-principles calculations indicate that fluorine may act as a carrier suppressor in the ZnON matrix by filling in the VN sites, which is an energetically favorable reaction. The properties of F-doped ZnON (ZnON:F) are investigated through various characterization methods, and the performance of the TFT devices incorporating ZnON:F active layers are studied next. In order to examine how the chemical bond properties are influenced by the presence of fluorine, X-ray photoelectron spectroscopy (XPS) analyses were carried out. The results indicate that as the ZnF2 target power increases to 6 and 10 W, the ratio of fluorine content increases up to 3.47 and 9.22 at. %, respectively. The amount of nitrogen on the other hand decreases down to 20.5 and 19.2 at. %, respectively. Note that the oxygen content remains relatively constant (Table 1.). Figures 1 (a)-(c) consist of the XPS O 1s peak spectra of the pure ZnON and ZnON:F 6, 10 W films. The O 1s peak was deconvoluted into two into two sub-peaks labelled O1 and O2, which are generally known to occur from oxygen forming metal-oxygen bonds and oxygen near oxygen vacant sites (OV) in oxide semiconductors, respectively. No apparent variation in the relative area ratios of sub-peaks O1 and O2 is observed, which implies that the incorporated fluorine does not affect the oxygen-related bonding states. Figures 1 (d)-(f) consist of XPS N 1s peak spectra of pure ZnON and the ZnON:F 6, 10 W layers. The N 1s peaks were deconvoluted into three different sub-peaks. The lowest energy sub-peak originates from nitrogen atoms in non-stoichiometric ZnxNy (including nitrogen vacancies), while the middle sub-peak arises from the nitrogen atoms in stoichiometric Zn3N2. The highest energy sub-peak represents mostly N-N bonds. The relative peak area ratios of the three sub-peaks within a single N 1s peak are represented in in table 2. Note that as the amount of incorporated fluorine increases, the relative fraction of nitrogen from stoichiometric Zn3N2 peak increases. Accordingly, the peak intensities from non-stoichiometric ZnxNy and N-N bonds diminish. The above results may be interpreted to occur from the fluorine anions passivating the vacant N sites that contribute to the sub-peak originating non-stoichiometric ZnxNy, so that the relative fraction of the latter appears to decrease with increasing F content, and consequently the sub-peak from stoichiometric Zn3N2 increases. The transfer characteristics of the devices based on ZnON and ZnON:F are shown in figure 2. Because N-rich ZnON was synthesized as the host material, a relatively large number of nitrogen vacancies is formed so as to convey a high free carrier density. ZnON device exhibits high off-state current, which diminishes as the fluorine content in the semiconductor increases. The representative transfer parameters are listed in table 3. The threshold voltages shift towards positive values with increasing F content. A field effect mobility of 151 cm2/Vs is obtained using ZnON:F 6 W as the semiconductor, with sufficiently low off-state current and threshold voltage near zero, so that the device may be used as a switching element in electronic applications. Figure 1

Feature-rich electronic properties of aluminum-adsorbed graphenes

The electronic properties of aluminum-adsorbed graphenes enriched by multi-orbital hybridizations are investigated by using first-principles calculations. The enriched features include the quasi-rigid red shifts of the carbon-related energy bands, the Al-dominated valence and conduction bands, and enhanced density of states (DOS) near the Dirac cone. The Al- and alkali-induced high free carrier densities are almost the same. There exist certain important differences among the Al-, alkali- and halogen-adsorbed graphenes, such as, the buckled or planar graphene, the preserved or seriously distorted Dirac cone, the presence or absence of the adatom-dominated valence bands, the free electrons or holes, the degenerate or split spin-related states, and the split peaks in DOS. The similarities and differences come mainly from the diverse orbital hybridizations in adatom-C bonds, reflected in the atom-dominated bands, the spatial charge distributions and the orbital-projected DOS.

Geometric and electronic properties of edge-decorated graphene nanoribbons.

Edge-decorated graphene nanoribbons are investigated with the density functional theory; they reveal three stable geometric structures. The first type is a tubular structure formed by the covalent bonds of decorating boron or nitrogen atoms. The second one consists of curved nanoribbons created by the dipole-dipole interactions between two edges when decorated with Be, Mg, or Al atoms. The final structure is a flat nanoribbon produced due to the repulsive force between two edges; most decorated structures belong to this type. Various decorating atoms, different curvature angles, and the zigzag edge structure are reflected in the electronic properties, magnetic properties, and bonding configurations. Most of the resulting structures are conductors with relatively high free carrier densities, whereas a few are semiconductors due to the zigzag-edge-induced anti-ferromagnetism.

Structural, optical, and electrical properties of strained La-doped SrTiO3 films

The structural, optical, and room-temperature electrical properties of strained La-doped SrTiO3 epitaxial thin films are investigated. Conductive La-doped SrTiO3 thin films with concentration varying from 5 to 25% are grown by molecular beam epitaxy on four different substrates: LaAlO3, (LaAlO3)0.3(Sr2AlTaO6)0.7, SrTiO3, and DyScO3, which result in lattice mismatch strain ranging from −2.9% to +1.1%. We compare the effect of La concentration and strain on the structural and optical properties, and measure their effect on the electrical resistivity and mobility at room temperature. Room temperature resistivities ranging from ∼10−2 to 10−5 Ω cm are obtained depending on strain and La concentration. The room temperature mobility decreases with increasing strain regardless of the sign of the strain. The observed Drude peak and Burstein-Moss shift from spectroscopic ellipsometry clearly confirm that the La addition creates a high density of free carriers in SrTiO3. First principles calculations were performed to help understand the effect of La-doping on the density of states effective mass as well as the conductivity and DC relaxation time.

Role of free carriers excited by ultrafast Bessel beams for submicron structuring applications

Ultrafast Bessel beams are ideal sources for high aspect ratio submicron structuring applications because of their nondiffracting nature and higher stability in nonlinear propagation. We report here on the interaction of ultrafast Bessel beams at various laser energies and pulse durations with transparent materials (fused silica) and define their impact on photoinscription regimes, i.e., formation of positive and negative refractive index structures. The laser pulse duration was observed to be key in deciding the type of the structures via excitation efficiency. To understand the relevant mechanisms for forming these different structures, the free carrier behavior as a function of laser pulse duration and energy was studied by capturing instantaneous excitation profiles using time-resolved microscopy. Time-resolved imaging and simulation studies reveal that low carrier densities are generated for ultrashort pulses, leading to soft positive index alterations via presumably nonthermally induced structural transitions involving defects. On the other hand, the high free carrier density generation in the case of longer pulse durations leads to hydrodynamic expansion, resulting in high aspect ratio submicron-size wide voids. Delayed ionization, carrier defocusing, and lower nonlinear effects are responsible for the confinement of energy, resulting in efficient energy deposition on-axis.

Copper Sulfide Nanocrystals with Tunable Composition by Reduction of Covellite Nanocrystals with Cu+ Ions

Platelet-shaped copper sulfide nanocrystals (NCs) with tunable Cu stoichiometry were prepared from Cu-rich covellite (Cu1.1S) nanoplates through their reaction with a Cu(I) complex ([Cu(CH3CN)4]PF6) at room temperature. Starting from a common sample, by this approach it is possible to access a range of compositions in these NCs, varying from Cu1.1S up to Cu2S, each characterized by a different optical response: from the metallic covellite, with a high density of free carriers and strong localized surface plasmon resonance (LSPR), up to Cu2S NCs with no LSPR. In all these NCs the valency of Cu in the lattice stays always close to +1, while the average -1 valency of S in covellite gradually evolves to -2 with increasing Cu content; i.e., sulfur is progressively reduced. The addition of copper to the starting covellite NCs is similar to the intercalation of metal species in layered transition metal dichalcogenides (TMDCs); i.e., the chalcogen-chalcogen bonds holding the layers are progressively broken to make room for the intercalated metals, while their overall anion sublattice does not change much. However, differently from the TMDCs, the intercalation in covellite NCs is sustained by a change in the redox state of the anion framework. Furthermore, the amount of Cu incorporated in the NCs upon reaction is associated with the formation of an equimolar amount of Cu(II) species in solution. Therefore, the reaction scheme can be written as: Cu1.1S + 2γCu(I) → Cu1.1+γS + γCu(II).

Compositional influence on the electrical performance of zinc indium tin oxide transparent thin-film transistors

In this work, zinc indium tin oxide layers with different compositions are used as the active layer of thin film transistors. This multicomponent transparent conductive oxide is gaining great interest due to its reduced content of the scarce indium element. Experimental data indicate that the incorporation of zinc promotes the creation of oxygen vacancies, which results in a higher free carrier density. In thin-film transistors this effect leads to a higher off current and threshold voltage values. The field-effect mobility is also strongly degraded, probably due to coulomb scattering by ionized defects. A post deposition annealing in air reduces the density of oxygen vacancies and improves the field-effect mobility by orders of magnitude. Finally, the electrical characteristics of the fabricated thin-film transistors have been analyzed to estimate the density of states in the gap of the active layers. These measurements reveal a clear peak located at 0.3eV from the conduction band edge that could be attributed to oxygen vacancies.

Structural and Electrical Properties of Single Crystalline Ga-Doped ZnO Thin Films Grown by Molecular Beam Epitaxy

High-quality Ga-doped ZnO (ZnO:Ga) single crystalline films with various Ga concentrations are grown on a-plane sapphire substrates using molecular-beam epitaxy. The site configuration of doped Ga atoms is studied by means of x-ray absorption spectroscopy. It is found that nearly all Ga can substitute into ZnO lattice as electrically active donors, a generating high density of free carriers with about one electron per Ga dopant when the Ga concentration is no more than 2%. However, further increasing the Ga doping concentration leads to a decrease of the conductivity due to partial segregation of Ga atoms to the minor phase of the spinel ZnGa2O4 or other intermediate phase. It seems that the maximum solubility of Ga in the ZnO single crystalline film is about 2 at.% and the lowest resistivity can reach 1.92 × 10−4 Ω·cm at room temperature, close to the best value reported. In contrast to ZnO:Ga thin film with 1% or 2% Ga doping, the film with 4% Ga doping exhibits a metal semiconductor transition at 80 K. The scattering mechanism of conducting electrons in single crystalline ZnO:Ga thin film is discussed.

Time resolved nonlinear spectroscopy at the band edge of 1D photonic crystals

Large refractive index changes have been measured at the band edge frequency of 1D photonic crystals (PCs). Results concerning both thin and thick samples of high and low refractive index contrasts, respectively, are presented. The very large value of the refractive index changes obtained at moderate pump powers thanks to the strong enhancement of the local intensity inside the PC opens the way to very small volume devices for optical signal processing. However, time resolved experiments demonstrate the photo-generation of high free carrier densities through two- or even three-photon absorptions, which are shown to be also strongly enhanced at the band edge of the PC. This drawback may most probably be circumvented by using lower pump intensities in PCs showing narrower resonances.

Zn2SiO4/ZnO Core/Shell Coaxial Heterostructure Nanobelts Formed by an Epitaxial Growth

Si-doped ZnO can be synthesized on the surface of the early grown Zn2SiO4 nanostructures and form core/ shell coaxial heterostructure nanobelts with an epitaxial orientation relationship. A parallel interface with a periodicity array of edge dislocations and an inclined interface without dislocations can be formed. The visible green emission is predominant in PL spectra due to carrier localization by high density of deep traps from complexes of impurities and defects. Due to band tail localization induced by composition and defect fluctuation, and high density of free-carriers donated by doping, especially the further dissociation of excitons into free-carriers at high excitation intensity, the near-band-edge emission is dominated by the transition of free-electrons to free-holes, and furthermore, exhibits a significant excitation power-dependent red-shift characteristic. Due to the structure relaxation and the thermalization effects, carrier delocalization takes place in deep traps with increasing excitation density. As a result, the green emission passes through a maximum at 0.25I(0) excitation intensity, and the ratio of the violet to green emission increases monotonously as the excitation laser power density increases. The violet and green emission of ZnO nanostructures can be well tuned by a moderate doping and a variation in the excitation density.

A study on influence of micropipes in SiC substrate on overgrown AlGaN/GaN HEMT DC characteristics

A deterioration mechanism of DC characteristics of AlGaN/GaN high-electron mobility transistors (HEMTs) fabricated around hollow cores that extend from micropipes in SiC substrates was studied. Various sizes of hollow cores were investigated to study the influence of size dependence. Prominent deterioration of the DC characteristics of HEMTs fabricated in the vicinity of hollow cores with a diameter of 5 μm was observed, while no major deterioration was observed for HEMTs fabricated around hollow cores whose diameters were 1.5 and 3 μm. Clear correlation between the size of hollow cores and free carrier densities at the peripheries of the cores was observed using micro-Raman imaging. The high density of free carriers around relatively large hollow cores causes deterioration of the DC characteristics of HEMTs fabricated in the vicinity of hollow cores. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Properties of III-N MOS structures with low-temperature epitaxially regrown ohmic contacts

A significant limitation in the fabrication of III-N MOSFET relates to the formation of ohmic contacts for enhancement-mode MOSFET structures. Unlike existing III-N HFET devices, which include a high free-carrier density two-dimensional electron gas (2DEG) in the semiconductor substrate, a MOSFET in either accumulation or inversion mode require low free-carrier concentrations for the semiconductor channel to have an off-state. The applied gate bias enhances the free-carrier density in the channel, turning on the FET. Unfortunately, a low free-carrier density substrate is problematic for the formation of ohmic contacts, a problem usually dealt with in silicon MOS through self-aligned ion implantation. The high annealing temperatures associated with activating implanted dopants to substitutional sites limits the use of ion implantation for III-N MOSFET fabrication. To overcome this difficulties, selected area epitaxial re-growth of doped III-N materials was developed to form source-drain contacts on otherwise low-doped III-N epitaxial substrates, yielding the needed N+/n−/N+ or N+/p−/N+ structures. Contact re-growth was performed by MOVPE using a silicon nitride dielectric mask defining plasma-etched recesses in the source-drain region. A significant acceleration in the growth rate and surface roughening was observed following re-growth relative to a non-selective area epitaxial growth due to the reduced fill-factor, motivating a general change in MOVPE-operating conditions during re-growth. As the re-growth was intentionally designed to limit the lateral extent of the source-drain regions, the MOVPE re-growth process was performed under conditions limiting lateral overgrowth. III-N MOSFET structures with epitaxial regrown contacts are projected to provide a pathway for low threshold voltage devices suitable for amplifier or logic applications.

Exact Self-Compensation of Conduction in Cd[sub 0.95]Zn[sub 0.05]Te:Cl Crystals in a Wide Range of Cd Vapor Pressures

The process of self-compensation in Cd0.95Zn0.05Te:Cl solid-solution crystals has been studied by annealing single crystals under a controlled Cd vapor pressure, with subsequent measurements of the Hall effect, photoluminescence, carrier lifetime and mobility, and photocurrent memory in the annealed crystals. By means of this annealing, conditions of thermal treatment that make it possible to fabricate low-conductivity samples with a low carrier density, 107–1011 cm−3, are defined. In these samples, a p → n conduction inversion is observed at a higher free-carrier density (n, p ≈ 109 cm−3) and the dependence of the electron density on the Cd vapor pressure exhibits a more gentle slope than in the case of CdTe:Cl crystals. The obtained data are discussed in terms of a self-compensation model in which intrinsic point defects act as acceptors with deep levels. This level is attributed to a Zn vacancy, which remains active at high Cd pressure.