CdS Films Research Articles

The effect of aluminum doping on nanostructured CdS: optical, structural and sensing characterization

CdS, and CdS: Al were grown onto glass bases via Chemical spray pyrolysis (CSP). XRD analysis of CdS films indicates a polycrystalline hexagonal structure with a predominant orientation of the (101) plane. The strain decreased from 28.55 to 25.66, and the grain size of undoped CdS films was around (13.51–12.14) nm as Al content rose. According to the results of AFM, CdS, CdS:2% Al, and CdS:4% Al all exhibit smooth surfaces with decreasing particle size in the range of (78.46), (69.75), and (42.20) nm, respectively. The root-mean-square roughness values for CdS and CdS:4% Al were 12.41 nm and 3.38 nm. According to AFM image, the surface roughness of CdS to CdS:4% Al were (9.74-5.16) nm. SEM images depict CdS films transitioning from flat islands (Undoped CdS) to uniform spherical nano-grains with Al doping. The result shows a decrease in absorption coefficient as Al content increased. The optical bandgap increased from (2.35-2.51) eV after doping. Results show that the extinction coefficient and refractive index are influenced by Al content. CdS film detects NO2 gas by resistance increase, impacted by Aluminum doping. Sensitivity decreases with an increase in Al doping in CdS films.

Sensing of nanostructured CdS thin films via several solution concentrations

Using chemical bath deposition (CBD) methods and various molarities, nanostructured CdS thin films were developed. XRD assured that these films were cubic polycrystalline, containing larger grains as the solution's concentration of cadmium ions increased. Dislocation density values dropped from 79.32 to 62.90 as a result, nevertheless. Also, the strain is lowered from 30.88 to 27.50. AFM results demonstrate that these films suffer a decrease in the value of average particle size, root mean square, and roughness with the molarity concentration. SEM images show CdS thin films at various molarities (0.10, 0.15, 0.20) M, indicating reduced grain size with increased concentration. The optical characteristics indicate a large band gap decreases from 2.46 eV to 2.34 eV and a high transmittance in the visible portion of the spectrum of more than 97.5%. The Refractive Index value changed from 3.23 to 3.11 as the content of cadmium ions increased. CdS films show p-type behavior, reducing resistance with NO2 gas, influenced by molar concentration. The sensitivity of CdS films to NO2 shows a decrement with increased molar concentrations.

Achieving over 860 mV Open‐Circuit Voltage in Low‐Ag Wide‐Bandgap Cu(In,Ga)Se2 Solar Cells Through Ion Diffusion and Band Structure Optimization

AbstractWide‐bandgap Cu(In, Ga)Se2 (CIGS) solar cells offer excellent thermal stability and significant potential for tandem applications. However, conventional CdS buffer layers exhibit poor band alignment with wide‐bandgap absorbers, resulting in severe interface recombination losses. Similarly, employing Zn(O,S) alone as a buffer layer leads to insufficient surface inversion, limiting its effectiveness. Here, a tailored interface engineering strategy is introduced using a 30 nm Zn(O,S)/15 nm CdS bilayer structure. The high conduction band value of Zn(O,S) establishes an optimal spike contact with the wide‐bandgap absorber, effectively suppressing interface recombination. Simultaneously, Cd ions diffuse from the modified thin CdS film to the Zn(O,S) layer, which sequentially enhances surface inversion and facilitates efficient carrier extraction in synergy with Zn ions. Additionally, Zn(O,S) offers superior absorber surface cleaning effects, ensuring a more uniform phase and potential distribution. Collectively, these improvements contribute to reduced interface recombination losses and lower reverse saturation current, leading to a power conversion efficiency (PCE) of 15.35% and an open‐circuit voltage (Voc) of 866 mV in a 1.46 eV wide‐bandgap CIGS device, which is the highest Voc in wide bandgap CIGS solar cells with low Ag content [Ag]/([Ag]+[Cu]) (AAC). This work provides critical insights into the development of high‐efficiency wide‐bandgap CIGS solar cells.

Reducing Parasitic Loss and Deep Defect Formation via Copper Doping Toward Highly Efficient Sb2Se3 Solar Cells

AbstractAntimony selenide (Sb2Se3) has great potential as a light‐absorbing layer in thin‐film photovoltaics because of its excellent photoelectric properties and superior stability. Presently, high‐efficiency Sb2Se3 solar cells use a heterojunction consisting of a p‐type Sb2Se3 absorber and an n‐type CdS layer. The power conversion efficiency (PCE) of Sb2Se3 solar cells is restricted by the low carrier concentration in the CdS layer, complex intrinsic deep defects of Sb2Se3, and unsuitable energy level band alignment in the junction. This paper presents a copper (Cu) doping strategy that achieves a synergistic doping effect, enabling controllable doping in both the n‐type CdS layer and p‐type Sb2Se3 absorber. First, proper Cu doping significantly enhances the short‐wavelength transmittance of CdS films and increases their n‐type carrier concentration. The Vbi in the CdS/Sb2Se3 heterojunction improves from 521 to 751 mV. Second, a post‐annealing process is performed to facilitate Cu diffusion from the CdS layer to the Sb2Se3 absorber. This approach successfully passivates intrinsic deep defect E2 and reduces the interfacial trap‐assisted nonradiative recombination losses. As a result, the Cu‐doped Sb2Se3/CdS solar cell presents a PCE of 10.23%, representing a 40% enhancement in PCE compared to the undoped CdS/Sb2Se3 heterojunction device.

Anomalous Electron Doping in CdS to Promote the Efficiency Improvement in Sb2Se3 Thin Film Solar Cells

AbstractThe quality of P‐N heterojunction is crucial for the performance of antimony selenide (Sb2Se3) solar cells and thus attracting urgent attention. In this work, the monovalent cation Ag+ is doped in CdS, which enhances the N‐type conductivity of CdS film anomalously and reduces its parasitic absorption simultaneously. Furthermore, Ag doping of CdS promotes the diffusion of Cd into the Sb2Se3 layer, forming CdSb defects, which enhances the P‐type conductivity of Sb2Se3 and reduces the density of deep‐level centers. With further chemical etching treatment on the CdS surface, the quality of the CdS/Sb2Se3 P‐N heterojunction is distinctly improved, making the energy band alignment of CdS/Sb2Se3 more favorable for carrier transportation. Finally, a remarkable efficiency of 8.14%, which is the highest efficiency among those with Jsc of 30.96 mA cm−2, is achieved for vapor transport deposition processed Sb2Se3 solar cells. This work provides a strategy to simultaneously optimize the CdS and Sb2Se3 functional layers and enhance the quality of P‐N heterojunction for efficient Sb2Se3 solar cells.

Comparative analysis of thermally evaporated nanoscale CdS thin film's structural, morphological, optical and nanomechanical properties

CdS nanoscale thin films were deposited on glass substrates at 1, 5 and 10 Å/s deposition rates by thermal evaporation process. The structural, morphological, compositional, optical and nanomechanical properties of CdS thin films were analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), UV-vis spectrophotometer and nanoindentation. XRD diffractogram indicate that the deposited CdS thin films have hexagonal structure with preferred orientation towards (002) plane and nearly stoichiometric composition. Various crystal structure parameters like lattice constant, crystallite size, defect density, dislocation density, lattice strain, number of crystallite per unit surface, stacking fault were determined. From XRD results, the calculated crystal structure parameters such as the crystallite size, microstrain and defect density were in the range of 20.4-14.7 nm, 7.74-10.62 and 2.3-4.52 × 1011 lines/cm2, at 1, 5 and 10 Å/s deposition rates, respectively .The AFM images indicated that the film's rms surface roughnesses were 2.73 nm, 2.94 nm and 3.18 nm at 1, 5 and 10 Å/s, respectively. The SEM images indicated that the films were uniform, continuous and defect free. The EDX examination revealed that at 1 Å/s deposition rate the film was nearly stoichiometic. The optical band gaps were determined to be in the range of 2.37-2.43 eV. Nanoindentation tests evaluated the hardness, Young's modulus, creep behavior and strain rate of CdS films. Hardness evaluated to be 0.14-1.48 GPa, 0.15-2.46 GPa, and 0.21-2.55 GPa at 1,5 and 10 Å/s deposition rate, respectively for 20-50 µN load. The Young's modulus decreases 1-5 Å/s deposition rate and becomes almost constant 5-10 Å/s deposition rate at 70 µN load. The characterization of CdS thin film recommend it as a favorable window layer in applications like photovoltaic, optoelectronic, thermoelectric and solar cells.

Probing into the low efficiency of CdS/SnS-based solar cells and remediation through surface treatments

Tin sulfide (SnS) is a highly promising photovoltaic absorption material in thin-film solar cells with abundant reserves, environmental friendliness, low cost and long-term stability. An efficiency of up to 4.8 % has been achieved for SnS absorber/CdS heterojunction solar cells where the CdS buffer layer is usually obtained by chemical bath deposition. However, current CdS/SnS devices often suffer from severe interface recombination loss, which deteriorates device performance. This report focuses on the CdS film surface to identify performance-degrading factors for CdS/SnS-based solar cells. XRD and XPS reveal numerous oxides on freshly fabricated CdS films increasing surface roughness and reducing conductivity. Herein, a method based on ammonium sulfide (AS) chemical treatment is proposed, which can effectively reduce the oxide content on the surface of CdS and optimize the band alignment, leading to the facilitation of charge carrier transport and the suppression of interface recombination. Consequently, the PCE of the FTO/CdS/SnS/Ag device is enhanced about three times (from 0.18 % to 0.47 %) with excellent moisture stability.

CBD-synthesized Mg-doped CdS thin films for hybrid solar cells and self-powered photodetectors

Mg-doped CdS samples were deposited via chemical bath deposition onto fluorine-doped tin oxide slides with varying levels of Mg-doping. Structural analysis revealed improved crystal quality in CdS films upon Mg incorporation. Morphological examinations indicated a reduction in grain size alongside appearance of smooth, void-free surfaces particularly evident at 3 % Mg-doping. Mg-doping also resulted in enhanced transparency of CdS films, notably at 3 % and 5 % within the visible spectrum. Efficient exciton dissociation was observed in hybrid solar cells based on 1 % and 3 % Mg-doped CdS, as evidenced by photoluminescence. Top-performing solar cell achieved an efficiency of 0.220 %, nearly seven times that of control device. 5 % Mg-doped CdS-based photodetectors exhibited favorable photosensing characteristics: a responsivity of 0.011 A/W, detectivity of 4.4 × 108 Jones, external quantum efficiency of 3.1 %, and rise/decay times of 26/25 ms at zero bias. These findings underscore beneficial effects of Mg-doping on both hybrid solar cell and self-driven photodetector performance.

Effect of magnetic field on the structural, optical, and electrical properties of CdS nanoparticles in distilled water by using pulsed laser ablation

In this study, we investigated the impact that the incorporation of a magnetic field has on the properties of cadmium sulfide CdS nanoparticles as well as the performance of an n-CdS/p-Si heterojunction photodetector that was developed by the use of the pulsed laser ablation in a liquid method. Nd:YAG laser pulses (1.064 μm, 550 mJ) were utilized to ablate cadmium sulfide CdS nanoparticles in water. The synthesized nanoparticles were shown to have a polycrystalline hexagonal structure, as evidenced by the findings of the X-ray diffraction experiment, the crystallite size for cadmium sulfide CdS decreased from 4.611 nm to 4.518 nm. The lattice constants of cadmium sulfide CdS nanostructures were determined to be a = 4.1302, c = 6.702, and c/a=1.622. The strain and dislocation density of cadmium sulfide CdS exhibited an increase. Images taken from a field emission scanning electron microscope demonstrated the formation of spherical nanoparticles on the surface. A magnetic field was applied, increasing the CdS film's crystallinity. As a consequence of this enhancement, the particle size of the CdS decreased from 25.18 nm to 12.17 nm. A comparison was made between this and the size of the crystallites that appeared when no magnetic field was present. The EDS spectrum of magnetically prepared cadmium sulfide CdS films indicates the presence of Cd and S, and the weight percentage ratios [Cd]/[S], increase from 3.72 to 3.80. The transmission electron microscopy (TEM) pictures of CdS samples that were generated using a magnetic field contained particles of small size with a mean of 10.10 nanometers. From the FT-IR spectra of cadmium sulfide CdS prepared using a magnetic field within 400–4000 cm−1, the peaks (bands) of cadmium sulfide CdS at 617 cm−1 represent the bending vibration of Cd-S. As a result of the influence of a magnetic field, the optical energy gap of CdS nanoparticles increased from 2.30 eV to 2.72 eV, as indicated by the UV-Vis study. From PL emission spectra the values of the energy band gap of cadmium sulfide CdS increased from 2.45 eV at 505.7 to 2.47 eV when a magnetic field was applied. CdS NP films produced under the influence of a magnetic field were identified as having n-type characteristics by Hall effect assessments, Particle mobility was influenced by particle size. The effect of applying a magnetic field on the efficiency of the n-CdS/p-Si photodetector was investigated and analyzed. When a magnetic field was applied during ablation, the responsivity of n-CdS/p-Si heterojunction photodetectors increased from 0.498 A/W to 0.830 A/W at 510 nm. This was the result of the application of the magnetic field.

Impact of hydrogen plasma treatment on ITO substrate for enhanced performance of CdS/CdTe solar cells

The indium tin oxide (ITO) film was treated with 100 W-power hydrogen plasma for 5 min before being used as a substrate to fabricate thermally evaporated CdS thin films. The structural, optical, and electrical properties of ITO and grown CdS films affected by pre-deposition plasma treatment were studied. SEM images show that the surface of ITO film becomes smoother after treatment. AFM analysis determines a decrease and increase in the surface roughness of ITO and CdS thin films after treating the ITO substrate. The XRD patterns show an improvement in the crystallinity of the fabricated thin films. Increasing the optical energy bandgap up to 3.699 eV and.2.481 eV for ITO and deposited CdS films respectively. So, design simple CdS/CdTe solar cells at a device temperature of 300 K. Enhancing the photovoltaic parameters and an increment of about 20 % in solar cell performance.

Hot probe technique for thin films Seebeck coefficient measurement

A new experimental method using a 50 μm diameter hand fabricated hot probe of Pt90/10Rh alloy is proposed as a tool to measure the Seebeck coefficient of thin films deposited onto electrically insulated substrates. A thermal model for heat transfer inside the probe and to the sample was developed to simulate the corresponding temperature distributions. Simulations showed that the ratio of the temperature rise in the contact point to the average temperature of the probe evolves basically independent on electrical current and film-substrate properties. Moreover, the values of contact radius and thermal contact resistance should not be necessary known, but only the pairs which are best fitting the probe thermal resistance in contact with the film-substrate. This brings a great simplification in respect with certain AFM based hot probe methods for which is necessary to determine these two parameters by calibration of the two substrates with known thermal conductivity. The values can be further used to evaluate the Seebeck coefficient of the sample with a macroscopic probe, within 1 % precision. By variance to the classical measuring methods, which resort to a heater-heat sink ensemble instrumented with thermocouples, heated metallic rods with built-in thermocouples or microfabricated structures, the proposed method is fast, reliable and of higher spatial resolution. The method was validated by measuring the Seebeck coefficient on CdS, Bi and Cr thin films reference samples, respectively.

An alternative chlorine-assisted optimization of CdS/Sb2Se3 solar cells: Towards understanding of chlorine incorporation mechanism

The current strategies in the development of Sb2Se3 thin film solar cells involve fabrication and optimization of superstrate and substrate device architectures, with the preferable choice for TiO2 and CdS heterojunction layers. For CdS-based superstrate cells, several studies reported the necessity to apply CdCl2 or other metal halide-based post-deposition treatment (PDT), highlighting improvement of CdS/Sb2Se3 device efficiency. However, the need, effect, and mechanism of such PDT are very often not described. Additionally, the fact that many groups have not succeeded in demonstrating its benefits suggests that this strategy is not straightforward, requiring a deeper understanding towards a more unified concept. The present study proposes an alternative approach to the challenging CdCl2 PDT of CdS in CdS/Sb2Se3 device, involving controllable Cl incorporation in CdS films by systematically varying the concentration of NH4Cl in the CBD precursor solution from 1 to 8 mM. Structural and electrical characterizations are correlated with advanced measurements of Scanning Kelvin Probe, surface photovoltage, and atomic force microscopy to understand the impact of Cl incorporation on the properties of CdS films and CdS/Sb2Se3 devices. The validity of Cl incorporation in the CdS lattice and interdiffusion processes at the CdS-Sb2Se3 interface is confirmed by secondary ion mass spectrometry analysis. It is demonstrated that incorporation of 1 mM of NH4Cl, as a Cl source in CBD CdS, can boost the PCE of CdS/Sb2Se3 by ∼20 %. With this approach, we offer new perspectives on the optimization methodology for Cl-based CdS/Sb2Se3 device processing and complementary understanding of the physiochemistry behind these processes.

Influence of deposition temperature and fluorine doping on CdS properties: Exploring applications in CdTe solar cells

CdS and CdS:F thin films were synthesized at 75 °C and 90 °C by CBD with NH4F as the fluorine dopant. The structural, morphological, optical, and electrical properties were investigated with varying F wt.%. XRD analysis revealed a coexistence of cubic and hexagonal phases with small crystallite sizes. Raman spectroscopy exhibited characteristic peaks of 1LO and 2LO, corresponding to longitudinal optical phonons. Scanning electron microscopy (SEM) images displayed dense films with excellent substrate adhesion and crystalline morphology. Optical analyses unveiled noticeable alterations in optical transmittance due to F doping, with bandgap values ranging between 2.3 to 2.4 eV. Electrical resistivity, typically in the order of kΩcm, was influenced by incorporating F atoms within the CdS lattice. Notably, the fabrication of CdS/CdTe solar cells yielded efficiencies of 5.53 % for undoped CdS films and 7.47 % when utilizing films doped with 0.00455 wt% fluoride, highlighting the beneficial impact of F incorporation on solar cell performance.

Development of photovoltaic and photodetection characteristics in CdS/P3HT devices through Al-doping

CdS thin films were deposited by chemical bath deposition onto FTO substrates with Al concentrations of 0, 1, 3, 5 and 6 %. X-ray diffraction revealed introduction of 1 % Al-doping reduced dislocation density and enhanced the crystal quality of CdS. Scanning electron microscopy confirmed a reduction in grain size in Al-doped CdS films compared to CdS. N3 and P3HT layers were spin-coated onto the prepared substrates, respectively. The fabrication of the solar cells was completed using Ag silver paste for the top contact. The lowest photoluminescence peak intensity was achieved for CdS (3 %Al):P3HT solar cell, indicating efficient exciton dissociation. 3 % Al-doped CdS-based device exhibited the highest efficiency at 0.210 %, nearly seven times that of reference device. CdS (3 %Al):P3HT device demonstrated the best photodetection characteristics, with a responsivity of 2.2 × 10-2 A/W, detectivity of 3.3 × 108 Jones, response time of 13 ms, and recovery time of 12 ms at zero bias voltage.

Effect of coating temperature on the properties of CdS thin films coated by nebulizer spray pyrolysis method for photodetection applications

Nanostructured CdS-based photodetectors have been focused on recent years because of their high photosensitivity and quick response time. This work reports the photodetector characteristics of CdS thin films prepared using a nebulizer-assisted spray pyrolysis technique by varying substrate temperatures. The X-ray diffraction (XRD) pattern of CdS films exhibits hexagonal structure with orientation along the (002) plane and CdS films deposited at 450 °C exhibits a higher crystallite size of 53 nm. Morphological analysis shows that the small grains become large spherical flakes at higher substrate temperatures. The optical studies showed that around the visible region, the films exhibit solid optical absorbance, and when substrate temperatures rise to 450 °C, the energy bandgap value decreases to 2.29 eV. The photoluminescence (PL) spectra exhibit two emission peaks: a broad peak at 525 nm and a sharp dominant peak at 680 nm. The CdS thin film deposited at 450 °C produced the highest photoresponsivity (R) of 37.1 × 10-2 A/W, detectivity (D*) of 268 x108 Jones, external quantum efficiency (EQE) of 120 %, and response/recovery times of 0.92/0.28 s under 532 nm illumination. The study suggests that CdS thin films are suitable for visible photodetector applications due to their simple and cost-effective production process.

Preparing of Cadmium Sulfide Nanoparticles and Studding their Optical and Structural Properties

Thin films of cadmium sulfide CdS have been deposited on glass substartes through chemical bath deposition, the films was examined using UV-Visible spectrometer and x-ray spectroscopy. the calculation of the energy gap show that it increases with deposition temperature and the x ray spectrum show also that the grain size decreases with deposition temperature, where the minimum grain size recorded was 26.17nm.

Photoelectrochemical conversion for ion-selective electrodes based on CdS semiconductor film

BackgroundThis study presents a novel photoelectrochemical (PEC) conversion method for ion-selective electrodes (ISEs) based on CdS semiconductor film. The motivation stems from the need to enhance the sensitivity and precision of ISEs for various analytical applications. ResultsWe synthesized CdS film on FTO conductive glass via a hydrothermal method and utilized this electrode as the working electrode. Under visible light irradiation, CdS generated photocurrent that is proportional to its applied voltage within a large potential window of ∼0.80 V. Ascorbic acid (AA) effectively inhibited electron-hole complexation, enhancing photocurrent stability. Potential modulation from ISEs acting as the reference electrode further regulated photocurrent generation, demonstrating excellent sensitivity and linearity for a wide range of ion concentrations. The method was validated by detecting serum calcium levels, showing agreement with traditional ISEs potentiometry and ICP-OES methods. SignificanceThis photoelectrochemical conversion strategy offers a promising approach for sensitive and accurate ion detection, with potential applications in clinical diagnostics and environmental monitoring.

Effect of doping (Sn and In) on CdS thin films for ammonia sensing at room temperature

The quantification and detection of Ammonia (NH3) are crucial due to their direct impact on human health and the environment, particularly when concentrations exceed 50 ppm in the atmosphere. To address this, thin films of pure CdS, Sn-doped CdS (CdS:Sn), In-doped CdS (CdS:In), and co-doped Sn and In (CdS:Sn:In) were prepared using the nebulized spray pyrolysis technique (NSP) for NH3 sensing studies. The X-ray diffraction (XRD) substantiated the single phase and polycrystallinity of the prepared films. Atomic Force Microscopy (AFM) reveals that CdS:In film attained higher RMS, average roughness, skewness (Rsk), and Rku values than the other prepared films. The estimated optical bandgap energy value is 2.44 eV for the CdS:In film. The photoluminescence (PL) studies reveal that the presence of defects. Emission bands observed around 523.35 nm, and 681 nm are attributed to band-to-band transition, and exciton recombination between sulphide vacancies (Vs2+) and the VB respectively. Essentially, the X-ray photoelectron spectroscopy (XPS) analysis reveals the existence of surface elements in various oxidation states. Surpassing the performance of other prepared films, CdS:In exhibited an exceptional response of 604.98 at 250 ppm, long-term stability and good repeatability, with rapid response and recovery times of 43.09 s and 5.6 s respectively.

Deposition of Fe-doped CdS films by spray pyrolysis from various precursors

Iron-doped cadmium sulfide films (Fe–CdS) were produced by spray pyrolysis using iron nitrate, chloride and sulfate as iron precursors. Based on experimental analysis data and thermodynamic calculations, it was found that the composition, uniformity and surface morphology of the films significantly depend on the nature of the iron precursor. It has been found that all synthesized Fe–CdS films can be used as master alloys for the manufacture of Fe:ZnSe laser elements.

Experimental and DFT studies of structural and optoelectronic properties of CdS, Zn doped CdS, and (Zn-Ni) co-doping CdS nanomaterials

Abstract This paper presents experimental and theoretical studies of binary semiconductor CdS, Zn:CdS, and (Zn-Ni) co-doped CdS. Thin films of pure CdS, Cd35ZnS36, and Cd34ZnNiS36 alloys grown by sol-gel spin coating were analyzed using X-ray diffraction, EDX, and UV-vis spectroscopy. The experimental results show the success of growing nanomaterials in hexagonal structures with crystallite sizes ranging from 1.6 to 2.11 nm and possessing band gaps in the region 2.30 -2.49 eV. Additionally, we investigate the structural and optoelectronic properties of these materials in the ground state using the density functional theory implemented in the WIEN2k software. The first principles calculations confirmed that the structural and optical properties of CdS align with the experimental results. For nanostructure Cd35ZnS36, the lattice parameters decrease, and the band gap increases to 2.85 eV with Zn doping. The (Zn-Ni) co-doped CdS structure optimization shows that the ferromagnetic configuration is more stable than the non-magnetic structure. The spin-polarized band structure investigations reveal that the majority spin-up channel is about 2.79 eV while the minority spin-down channel is around 2.19 eV. These results increase the importance of Zn:CdS and CdZnNiS alloys for optoelectronic and spintronic applications. The calculated optical properties of CdS, Zn:CdS, and (Zn-Ni) co-doped CdS show slight changes in refractive index and extinction coefficient with the doping and a quantitative agreement with the experimental findings.