CdS Nanowires Research Articles

Metal-free azo dyes anchored on CdS nanowires: Subtle solar cell exploration through experimental and DFT studies

Herein, as-synthesized azo dye (E)-2-isopropyl-5-methyl-4-((4-(4-nitrophenyl) thiazol-2-yl) diazenyl) phenol (D2) has been anchored on a high surface area one dimensional CdS nanowires (NWs) in thin film form. CdS nanowires have been grown through Cd(OH)2 template formation followed by conversion to CdS by ion-exchange route. The light-electricity conversion efficiency of the CdS-Azo dye-based solar cell has shown about 5-fold remarkable surge (0.159%) compared to the bare CdS (0.03%) with I3−/I− redox mediator under standard AM 1.5 illumination (100 mW cm−2). Albeit, the DFT studies revealed a higher band gap for pristine D2, alluringly it has depicted higher light-electricity conversion efficiency among the fabricated thin film solar cells after sensitization. The relative increase in sensitivity after sensitization is attributable to facile dye regeneration. Furthermore, after the co-sensitization of CdS thin film with equimolar cocktails of as-synthesized dyes and a natural dye Betanin (Bn), less efficiency was depicted ascribable to plausible dye aggregation upon blending.

2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene)malononitrile functionalized diketopyrrolopyrrole: Synthesis and solar cell applications

Diketopyrrolopyrrole (DPP) functionalized with 2-(3-cyano-4,5,5-trimethylfuran-2(5H)-ylidene) malononitrile (TCF) material coined as DPP-TCF was designed and synthesized. DPP-TCF exhibited strong absorption bands in solution as well as thin-film form. Herein, we report construction of dye sensitized solar cells (DSSCs) based on DPP-TCF anchored on CdS nanowires (NWs) coated on fluorine doped tin oxide (FTO) coated glass substrate with the device architecture FTO/CdS compact/CdS nanowire/DPP-TCF chromophore/electrolyte/ platinum coated FTO. As-fabricated DSSC device based on DPP-TCF and CdS nanowires exhibited power conversion efficiency (η) of 0.427%. Thus, the present work successfully displayed the utilization of DPP-TCF as an efficient light harvester in DSSC applications. This approach can also be employed to design and development of other DPP based organic molecular chromophores for DSSC applications.

Simultaneous H2 fuel evolution and value-added organic transformation from a one-dimensional noble-metal-free photocatalyst with spatially separated catalytic sites

Replacing the sluggish O2-producing half-reaction with value-added organic oxidations in water photolysis systems is deemed more practical to generate H2 fuels. While loading of dual cocatalysts for both half-reactions onto nanoscale photocatalysts is highly beneficial for photocatalysis, developing such nanomaterials that are low-cost, stable and easy-to-synthesize remains challenging. Here, noble-metal-free CdS-Co3O4-NiSx nanodumbbells with spatially separated half-reaction sites are designed to simultaneously generate H2 and oxidize benzylamine without any sacrificial agent. In this nanoarchitecture, electron-collecting NiSx and hole-collecting Co3O4 are anchored at the tips and sidewall of CdS nanowires, respectively, to lower the proton reduction and benzylamine oxidation energy barriers, respectively, thus establishing a dual-functional photocatalytic redox system. With significantly promoted charge separation and half-reaction kinetics, the nanodumbbells can produce H2 (47 mmol∙g−1∙h−1) ca. 70 times faster than pure CdS, along with simultaneous benzylamine oxidation. Our findings provide a viable one-dimensional photocatalyst design strategy for various coupled half-reactions.

A visible-light-driven photoelectrochemical sensor for the sensitive and selective detection of chlorpyrifos via CoS2 quantum dots/CdS nanowires nanocomposites with 0D/1D heterostructure

A visible-light-responsive photoelectrochemical (PEC) sensor was proposed for the sensitive and selective analysis of chlorpyrifos (CPF) by synergistically using CoS2 quantum dots (QDs) and CdS nanowires (NWs). The CdS NWs were first prepared by the solvothermal method and subsequently combined with CoS2 QDs to produce CoS2/CdS product with 0D/1D heterostructure. It turned out that the so-obtained nanocomposites with 0D/1D heterostructure could greatly suppress the recombination of photoinduced electrons and holes, and the electrode modified with this composite could exhibit preferable PEC performance and photocurrent signal compared to the one with CdS or CoS2. After the addition of CPF, the photocurrent signal of the proposed PEC sensor was found to be selectively decreased because of the specific chelation between the cobalt sites of CoS2/CdS and the sulfur, nitrogen-atoms of CPF, which might block the electrons transferring process. The proposed PEC sensor could detect CPF in concentrations that linearly span from 0.030 to 100 ppb with an ideal detection limit of 0.010 ppb, which performances are much better than those of currently used analytical methods. Furthermore, this work may establish a framework for the development of various PEC sensing platforms with 0D/1D heterostructure for the quantitative assay of environmental pollutants like CPF.

Benzothiazole functionalized diketopyrrolopyrrole photosensitizer for CdS nanowire based DSSC applications

Although dye sensitized solar cell (DSSC) make promising progress for solar energy conversion to electrical energy, there are still great need for further research work to develop an efficient sensitizer with a simple synthetic protocol. In this study, two chromophores (E)-2-(benzo[d]thiazol-2-yl)-3-(5-(2,5-bis(2-ethylhexyl)-3,6-dioxo-4-(thiophen-2-yl)-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrol-1-yl)thiophen-2-yl)acrylonitrile (DPP-BTH1) and 3-(5-(2,2-bis(benzo[d]thiazol-2-yl)vinyl)thiophen-2-yl)-2,5-bis(2-ethylhexyl)-6-(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (DPP-BTH2) are developed with broad range of absorption. The benzothiazole subunit 2-(benzo[d]thiazol-2-yl)acetonitrile (BTH1) and bis(benzo[d]thiazol-2-yl)methane (BTH2) auxiliary subunits were incorporated at the 5-(2,5-bis(2-ethylhexyl)-3,6-dioxo-4-(thiophen-2-yl)-2,3,5,6-tetrahydropyrrolo[3,4-c]pyrrol-1-yl) thiophene-2-carbaldehyde (DPP) core. DSSC devices with DPP-BTH1/CdS and DPP-BTH2/CdS nanowire photoelectrode under AM 1.5 G sun illumination exhibited power conversion efficiency of about 0.30 % and 0.45 %, respectively. The PCE is three and four-fold higher than that of bare CdS nanowire-based DSSC devices. These simple chromophores provide a promising perspective for next-generation photovoltaic devices to harvest sunlight efficiently.

Visible light-driven photocatalytic H2 evolution and dye degradation by electrostatic self-assembly of CdS nanowires on Nb2C MXene

Photocatalytic H2 evolution and dye degradation using a semiconductor photocatalytic system are considered to be the most appropriate techniques for solving current energy crises and environmental issues. However, the effective separation and utilization of photoexcited charge carriers is the bottleneck of a photocatalytic system. To tackle this problem, we report an efficient photocatalytic system of CdS nanowires (NWs) electrostatically self-assemble on the Nb2C MXene cocatalyst. The synthesized CdS/Nb2C composites indicate that the CdS NWs are homogeneous and uniformly distributed on the accordion type Nb2C MXene cocatalyst, which was confirmed via different characterization techniques such as SEM, TEM, HRTEM, and elemental mapping. Furthermore, the electrochemistry analysis, PL, TRPL, EPR, and UV DRS spectra indicate the synthesized CdS/Nb2C composites exhibit appreciable enhancement in the separation of photoexcited charge carriers and transfer ability by inhibiting the annihilation factor and improving the light absorption. Therefore, the photocatalytic H2 evolution efficiency of the optimized CdS/Nb2C composite reveals 2.53 mmol g−1 h−1, which was 5.34 times superior to CdS NWs. Moreover, the optimized sample manifested efficient stability even after five consecutive cycles and has an apparent quantum efficiency (AQE) of 3.69% with monochromatic light at 420 nm. Furthermore, the optimized CdS/Nb2C composite also manifests superior performance for photocatalytic degradation of Rhodamine B (RhB), which was a 99% degradation of RhB under light illumination for 20 min, much higher than pristine CdS NWs. This study shows that Nb2C MXene can be used as a potential noble metal free cocatalyst in a photocatalytic system to overcome environmental and energy crises.

Synthesis of phenothiazine dyes featuring coumarin unit and CdS NWs as photoanodes for efficient dye- sensitized solar cells

In this study, we have inventively developed novel metal-free organic dyes (PPR and PCTR) through a multistep synthetic route. These designed novel dye molecules were integrated onto 1-D CdS nanowires, serving as excellent sensitizer for the efficient light energy harvesting components in the context of dye-sensitized solar cells. Through a facile and efficient approach to solution chemistry, we have attained the unified architecture of CdS nanowires into a multifaceted nano-network, highlighting the absolute efficiency of this approach. Density functional theory (DFT) simulations, united with scrupulous optical and electrochemical investigations, have been employed to assess the sensitizing ability of engineered materials. Remarkably, dye-anchored CdS NWs reveals prolonged light absorption coverage through visible solar spectrum than unmodified CdS nanowire counterparts. Elaborate photovoltaic study reveals, the well-matched energy band alignment, particularly LUMO levels of the PCTR than PPR dye, with CdS NWs, stands as the substratum for the dramatic improvement observed in both the Jsc and Voc attributes. This growth interprets into an overwhelming 2.6-fold and 2.0-fold enhancement in the overall solar cell performance for PCTR and PPR dyes respectively, exceeding the ability of CdS NWs under standard light conditions. Improving external quantum efficiency (EQE) and impeccably correlating with results of complex optical investigations. This significant achievement intends to highlight solar energy conversion approaches and alter the field of light-driven technologies.

Ab-initio study of electronic, magnetic, and optical properties of Ni mono-doped and (I, Ni) co-doped CdS nanowires

Diluted magnetic semiconductors typically display induced ferromagnetism and spin-dependent interactions at high Curie temperatures, which is advantageous for application in magneto-electronic devices. The causes of ferromagnetism and optical emission dynamics, which have complex microstructural and compositional properties, are still not fully understood. Here, using first-principles calculations, the impact of Ni(II) ion substitution on the electronic, optical, and magnetic properties of CdS NW has been studied for the first time. The results show that when the size of the nanowire increases, the bandgap and binding energy decrease. The most favorable site for Ni doping was found to be at the surface of the nanowire. The most stable configuration with Ni ions on the surface of the nanowire has AFM as its ground state, which may be described using the super-exchange mechanism. The ground state configuration shifts from AFM to FM due to the addition of the extra electron provided by iodine (I) co-doping, and the estimated Curie temperature is expected to be higher than the ambient temperature. The fundamental bandgap of CdS nanowire is redshifted with Ni(II) doping, and the observed d-d intra-band transition in the absorption spectra at the low energy side of the optical bandgap is well consistent with the experimental results. Furthermore, the optical bandgap and d-d intra-band transitions in the optical absorption spectra are correlated with the magnetic coupling between Ni(II) ions, and we find a red-shift/blue-shift of d-d intra-band transition peaks and bandgap in the FM/AFM coupled ions system, supporting the experimental observations. The enhanced optoelectronic and magnetic properties of (Ni, I) co-doped CdS nanowires suggest their possible application in spintronic and optoelectronic devices, such as remote sensing and photovoltaics.

Highly Selective Photocatalytic Conversion of 5‐Hydroxymethyl‐2‐furfural to 2,5‐Diformylfuran over Gold Ion Exchanged Cadmium Sulfide Nanowire

Abstract5‐Hydroxymethyl furfural (HMF) obtained from biomass can be converted to 2,5‐diformylfuran (DFF), a valuable chemical intermediate. However, the typical HMF oxidation process requires energy consumption such as high temperature and oxygen pressure. Herein, Au2S decorated CdS nanowires (denoted as Au2S@CdS NWs) are fabricated by a simple ion exchange method and applied as a heterostructure photocatalyst system for HMF oxidation under mild conditions. Under visible light irradiation, the photocatalytic performance of Au2S@CdS NWs is significantly enhanced compared with pristine CdS NWs, in which Au2S (0.25%)@CdS NWs achieve the high DFF yield (≈95%) for 4 h reaction time. This result means that the heterogeneous interface formed between CdS NWs and Au2S promotes the separation efficiency of photogenerated charges, which leads to high catalytic activity. Moreover, Au2S (0.25%)@CdS NWs work well for HMF conversion to DFF under anaerobic and aerobic conditions. Control experiments and characterization are conducted to investigate each reaction mechanism. Consequently, it is found that the photogenerated hole directly oxidizes HMF to DFF under anaerobic conditions and the1O2produced from oxygen is the active species for HMF conversion to DFF under aerobic conditions.

Efficient Fiber‐to‐Chip Interface via an Intermediated CdS Nanowire

AbstractAn efficient fiber‐to‐chip interface via an intermediated CdS nanowire is demonstrated. The fiber mode is firstly squeezed through a fiber taper drawn at the end of a single‐mode fiber, then evanescently coupled into an intermediated CdS nanowire with a longitudinally tapering profile, and finally coupled into an on‐chip silicon waveguide (SiW) via a waveguide taper fabricated on it. Since the fiber‐nanowire‐SiW cascade structure is designed to match effective indices in each coupling area, such a fiber‐to‐chip interface ensures a bidirectional coupling efficiency up to 90% and a 3‐dB bandwidth over 100 nm in experiments. The difference of coupling efficiencies between the TM or TE modes is less than 0.5 dB in the spectral range of 1545–1635 nm. The footprint of the on‐chip coupling structure is about 10 µm in size. The results may provide a compact, efficient, and versatile fiber‐to‐chip interface in applications including optical interconnects, coherent communication, and quantum optical circuitry.

Hierarchical CdS/Ni3S4/Ni2P@C Photocatalyst for Efficient H2 Evolution under Visible-Light Irradiation.

Structural and morphological modulations play a crucial role in increasing the surface active sites of semiconductor photocatalysts for visible-light-driven water splitting. To fabricate a novel CdS/Ni3S4/Ni2P@C heterostructure, we first prepared carbon-encapsulated Ni3S4/Ni2P (Ni3S4/Ni2P@C) with a high surface area by sequential carbonization and phosphorization of a Ni-metal-organic framework (MOF) precursor. Combined characterization and photoelectrochemical measurement results reveal that the assembly of CdS nanowires and highly porous Ni3S4/Ni2P@C can enhance the visible-light response capability of the CdS/Ni3S4/Ni2P@C heterostructure catalyst by reducing the forbidden band gap of CdS. The hydrogen production rate of 21.56 mmol h-1 g-1 for CdS/Ni3S4/Ni2P@C with a Ni3S4/Ni2P@C mass fraction of 10 wt % was 26 times higher than that of CdS in a photolytic aquatic hydrogen system. A possible mechanism for the photocatalytic enhancement of the Ni3S4/Ni2P@C co-catalyst was systematically investigated and discussed. This research opens a new strategy for constructing ternary heterojunction photocatalysts via MOF precursors.

In-situ CdS nanowires on g-C3N4 nanosheet heterojunction construction in 3D-Optofluidic microreactor for the photocatalytic green hydrogen production

Herein, we reported a simple and cost-effective fabrication method to develop an effective corrugated serpentine OFMR (C-SOFMR) with advanced features, such as expansion/contraction and wavy microstructure. A laminar flow with no back mixing was observed in plain serpentine OFMR (P-SOFMR). While, stretching and folding of fluid along with back mixing was observed in C-SOFMR. Further, the CdS nanowires on g-C3N4 nanosheet (CN/CdS) heterojunction was synthesized in situ both P-SOFMR and C-SOFMR and utilized the device for the photocatalytic green hydrogen generation. The CN/CdS heterojunction endowed with narrow band gap energy (2.01 eV). The longer CdS nanowires (∼110 nm) benefit the electronic interface with CN in the CN/CdS heterojunction and lead to the spatial separation (reduced recombination) of excitons along the CdS axial direction. The charges generated were utilized efficiently for the HER reaction in both P-SOFMR and C-SOFMR at higher flow rates attributing to the rapid micro-mixing and mass transfer. The CN/CdS heterojunction showed the highest photocatalytic activity (6.38 μmol h−1 in C-SOFMR and 6.16 μmol h−1 in P-SOFMR at 1.0 mL min−1) due to its good optronic properties. This study is a path forward for the utilization of advanced optofluidic devices to produce green hydrogen directly from solar energy.

Super-Broad-Wavelength-Range Polarization-Selective Exciton-Polariton in Sn-Doped CdS Nanowires

The polarization-coupled exciton-polariton is promising for applications in polarization-associated optoelectronic devices. Although a room-temperature exciton-polariton has been observed in many nanostructures, super-broad-wavelength-range polarization-selective exciton-polariton output remains elusive. Here, a room-temperature exciton-polariton is demonstrated by angle-resolved photoluminescence (ARPL) spectroscopy in Sn-doped CdS nanowires. Due to the reduction of cross-section radius, the polarization splitting between transverse electric (TE) and transverse magnetic (TM) modes increases. The maximum splitting value can reach 45 meV when the cross-section is 0.548 μm. Taking advantage of the interaction’s polarization effect between the photon and exciton, polarization-selective exciton-polariton output is realized, and the wavelength tuning range is more than 200 nm. These results provide useful enlightenment to construct polarization polaritonic devices at room temperature.

Coherent nanointerface between light-harvesting and catalytic transition metal sulfides for efficient photochemical conversion

Creating atomically coherent interfaces can sharpen the physiochemical properties and functionalities of nanomaterials for efficient energy conversion via manipulating the charge flow. While coherent interfaces can be built between transition metal dichalcogenides with structural similarities and weak interlayer van der Waals interactions, it remains challenging to realize interfacial coherency with more generic transition metal chalcogenides via cost-effective wet chemical routes. Here we establish a coherent CdS(010)|CoS(010) interface via in-situ heteroepitaxial growth of CoS nanoflakes onto CdS nanowires. The uniform and oriented distribution of CoS nanoflakes on the CdS nanowires features an interesting “leaves-on-a-branch” nano-architecture with coherent interface and well-aligned energy levels, allowing efficient separation of photoexcited charge carriers. Combined with the outstanding proton reduction kinetics of the CoS “nanoleaves”, striking photochemical solar-to-hydrogen conversion performance can be obtained. Our findings provide a viable design strategy of nanojunctions with atomic level coherency and great application prospect in catalysis, nanoelectronics and many others.

Label-Free Electrochemiluminescent (ECL) Determination of Mercury (II) Based upon the Cation Exchange Reaction with Cadmium Sulfide Nanowires

An electrochemiluminescence (ECL) sensor for mercury (II) was developed based on the cation exchange reaction between Hg2+ and CdS due to the large difference in the sedimentation equilibrium constant. To fabricate the sensor, CdS nanowires (CdS NWs) serving as the emitter were introduced upon a glass carbon electrode (GCE). Gold nanoparticles (Au NPs) with excellent electrical conductivity were introduced on the surface of CdS NWs/GCE to enhance the sensor performance. In the presence of Hg2+, the electrochemiluminescence of the sensor decreased. The electrochemiluminescence intensity was negatively correlated with the concentration of Hg2+. The excellent performance of Au NPs:CdS NWs/GCE, combined with the difference in the CdS and HgS sedimentation equilibrium constants, endows the sensor with good selectivity and sensitivity for the analyte. A long linear range from 6.7 × 10−15 M to 1.0 × 10−8 M was obtained for Hg2+ with a detection limit of 5.0 × 10−15 M. The applicability of the method was validated by the analysis of water and lake water.

Enhanced photocatalytic hydrogen evolution by piezoelectric effects based on MoSe2/Se-decorated CdS nanowire edge-on heterostructure

The build-in electric field by the construction of heterojunction is one of the most promising strategies to suppress the recombination of photogenerated carriers. Here, we reported a piezo-photocatalytic system composed of Se-decorated CdS nanowires and few-layered edge-on MoSe2 nanosheets for efficient H2 generation by two-pot hydrothermal synthesis. The few-layered MoSe2 exposed abundant edge sites for hydrogen evolution reaction (HER). The activity of 20-MoSe2/CdS0.95Se0.05 (20-MS/CSS, with 20 mol% of MoSe2 loading) nanocomposite casted a remarkable photocatalytic HER performance, with a rate of 47.3 mmol h−1 g−1. Moreover, MoSe2 nanosheets deformed to generate the piezoelectric polarization field under magnetic stirring, which rendered efficient separation of photogenerated carriers, resulting in a piezo-photocatalytic synergistic effect. As a result, the HER of 20-MS/CSS at 900 rpm for piezo-photocatalysis was 59.1 mmol h−1 g−1, which was 1.25 times that of 20-MS/CSS for photocatalysis. Meanwhile, the photoelectrochemical measurements further visualized the piezo-photoelectric synergy. This study exposes a new way for utilizing mechanical energy to improve photocatalytic performance, and achieving high piezo-photocatalysis.

In vivo tracking of individual stem cells labeled with nanowire lasers using multimodality imaging.

Emerging cell-based regenerative medicine and stem cell therapies have drawn wide attention in medical research and clinical practice to treat tissue damage and numerous incurable diseases. In vivo observation of the distribution, migration, and development of the transplanted cells is important for both understanding the mechanism and evaluating the treatment efficacy and safety. However, tracking the 3D migration trajectories for individual therapeutic cells in clinically relevant pathological environments remains technically challenging. Using a laser photocoagulation model in living rabbit eyes, this study demonstrates a multimodality imaging technology integrating optical coherence tomography (OCT), fluorescence microscopy (FM), and lasing emission for in vivo longitudinal tracking of the 3D migration trajectories of individual human retinal pigment epithelium cells (ARPE-19) labeled with CdS nanowires. With unique lasing spectra generated from the subtle microcavity differences, the surface-modified nanowires perform as distinct spectral identifiers for labeling individual ARPE-19 cells. Meanwhile, with strong optical scattering and natural fluorescence emission, CdS nanowires also served as OCT and FM contrast agents to indicate the spatial locations of the transplanted ARPE-19 cells. A longitudinal study of tracking individual ARPE-19 cells in rabbit eyes over a duration of 28 days was accomplished. This method could potentially promote an understanding of the pharmacodynamics and pharmacokinetics of implanted cells in the development of cell-based therapies.

Improving reliability of window-absorber solar cells through CdS nanowires

CdS nanowires/CdTe solar cells (NSC) with graphite/Cu and ZnTe/Cu contact have been fabricated and their reliabilities were conducted in ambient air at 120 °C for 180 h. Counterpart planar CdS film/CdTe solar cells (PSC) are fabricated and characterized for comparison. Planar CdS film/CdTe solar cells with graphite contact exhibit roll-over of J-V characteristics and 52.5% of efficiency loss after elevated temperature test. Significantly enhanced reliability has been demonstrated in the nanowire solar cells, regardless of back contact types. Nanowire solar cells eliminates roll-over. With initial efficiency of 10%, the nanowire solar cells coated with Cu/graphite contact improved degradation of efficiency by 2.75 times and 52%, compared with efficiency degradation in the PSC with Cu/graphite contact and ZnTe contact respectively. Nanowire structures combined with ZnTe contact enable efficiency of the cells to be degraded by only 4.5%, which is 3.7 times more stable than 21.4% efficiency degradation in the counterpart PSC. Numerical simulation models demonstrate that donor defect concentration and interface state density of planar solar cells is increased by two times and two orders of magnitude respectively. However, for NSC-GC, such increase in donor defects and interface states are much lower than those of PSC-GC and acceptor defects in CdS nanowires maintain same concentration at baseline and after elevated temperature test. Reliability mechanism is thought as that impurity diffusion from back contact into CdS nanowires is hindered arising from characteristics of CdS nanowire structures.

Surface decorated Ni sites for superior photocatalytic hydrogen production

AbstractPrecise construction of isolated reactive centers on semiconductors with well‐controlled configurations affords a great opportunity to investigate the reaction mechanisms in the photocatalytic process and realize the targeted conversion of solar energy to steer the charge kinetics for hydrogen evolution. In the current research, we decorated isolated Ni atoms on the surface of CdS nanowires for efficient photocatalytic hydrogen production. X‐ray absorption fine structure investigations clearly demonstrate the atomical dispersion of Ni sites on the surface of CdS nanowires. Experimental investigations reveal that the isolated Ni atoms not only perform well as the real reactive centers but also greatly accelerate the electron transfer via direct Ni–S coordination. Theoretical simulation further documents that the hydrogen adsorption process has also been enhanced over the semi‐coordinated Ni centers through electronic coupling at the atomic scale.

Facet‐Driven Vapor Phase Growth of Directional Tin‐Doped CdS Nanowires on Sapphire Surface for Photodetectors

Orientation‐controlled large‐area synthesis of nanowires (NWs) is key to their direct integration into circuits and devices for functional exploitation. Herein, the vapor–liquid–solid process yields planar arrays of tin‐doped CdS NWs with precise crystallographic orientation on flat and faceted sapphire surfaces. The nanopatterned catalyst and epitaxial correlation of each surface determine NWs’ exact position, yield, and orientation, while the graphoepitaxial effect steers their growth along the nanochannels. The incorporation of dopants widens the emission spectrum beyond the bandgap, which facilitates enhanced optical transport in NWs. Electron‐beam lithography (EBL) is employed to fabricate photodetector on individual NW, which demonstrates high photoresponsivity and fast response. Graphoepitaxial effect‐based assembly of highly ordered horizontal NW arrays and their facile self‐integration into devices for modern applications, including LEDs, biomedical or photoelectric sensors, photovoltaic cells, and visible span integrated optoelectronic and photonic systems, have promising prospects.