Lifetime Of Photoexcited Carriers Research Articles

Low‐Temperature Synthesis of Stable CaZn2P2 Zintl Phosphide Thin Films as Candidate Top Absorbers

AbstractThe development of tandem photovoltaics and photoelectrochemical solar cells requires new absorber materials with bandgaps in the range of ≈1.5–2.3 eV, for use in the top cell paired with a narrower‐gap bottom cell. An outstanding challenge is finding materials with suitable optoelectronic and defect properties, good operational stability, and synthesis conditions that preserve underlying device layers. This study demonstrates the Zintl phosphide compound CaZn2P2 as a compelling candidate semiconductor for these applications. Phase‐pure, ≈500 nm‐thick CaZn2P2 thin films are prepared using a scalable reactive sputter deposition process at growth temperatures as low as 100 °C, which is desirable for device integration. Ultraviolet‐visible spectroscopy shows that CaZn2P2 films exhibit an optical absorptivity of ≈104 cm−1 at ≈1.95 eV direct bandgap. Room‐temperature photoluminescence (PL) measurements show near‐band‐edge optical emission, and time‐resolved microwave conductivity (TRMC) measurements indicate a photoexcited carrier lifetime of ≈30 ns. CaZn2P2 is highly stable in both ambient conditions and moisture, as evidenced by PL and TRMC measurements. Experimental data are supported by first‐principles calculations, which indicate the absence of low‐formation‐energy, deep intrinsic defects. Overall, this study shall motivate future work integrating this potential top cell absorber material into tandem solar cells.

Wide-Range and Multistate Work Functions of Organometallic Halide Perovskite Films Regulated by Ferroelectric Substrates.

Work function of organometallic halide perovskite (OHP) films is one of the most crucial photoelectric properties, which dominates the carrier dynamics in OHP-based devices. Despite surface treatments by additives being widely used to promote crystallization and passivate defects in OHP films, these chemical strategies for modulation of work functions face two trade-offs: homogeneity on the surface versus along the thickness; the range versus the accuracy of modulation. Herein, by using ferroelectric substrates of uniform polarization and subnanometer roughness, homogeneous CH3NH3PbI3 films are fabricated with five states of work functions with large spanning (∼0.8 eV) and high precision (sd ∼ 0.01 eV). We reveal that the ferroelectric polarizations and the smooth surfaces regulate CH3NH3+ orientations and suppress distortions of PbI6 octahedrons. The wide-range and multistate work functions originate from the ordered CH3NH3+ orientations and PbI6 octahedrons, which result in intensity enhancements and wavelength shifts in photoluminescence with a 30-fold increase of photoexcited carrier lifetime.

Enhancement of photoexcited carrier lifetime in an InGaAs/GaAsP wire-on-well quantum structure investigated by excitation-power-dependent photoluminescence measurements

Enhancement of photoexcited carrier lifetime in an InGaAs/GaAsP wire-on-well quantum structure investigated by excitation-power-dependent photoluminescence measurements

Surface-state-related carrier dynamics of GaAs determined by UV-visible pump-probe terahertz spectroscopy

The surface velocity and the bulk lifetime of photo-excited free carriers in GaAs were measured using an optical-pump and THz-probe time-domain technique. By varying the pump laser photon energy from 1.56 to 4.15 eV, we observe that the surface velocity drops abruptly from 0.7×106 cm/s down to 0.2×106 cm/s at 2.5 eV, while the bulk lifetime remains almost constant. We tentatively explain this step-like behavior of the surface velocity vs the photon energy by a trapping of the free carriers at surface states, whose density of states shows a maximum at 2.5 eV.

Fabrication and Characterization of Electrospun Cu-Doped TiO2 Nanofibers and Enhancement of Photocatalytic Performance Depending on Cu Content and Electron Beam Irradiation.

Titanium dioxide (TiO₂) is a widely studied material with many attractive properties such as its photocatalytic features. However, its commercial use is limited due to issues such as deactivation in the visible spectrum caused by its wide bandgap and the short lifetime of photo-excited charge carriers. To overcome these challenges, various modifications could be considered. In this study, we investigated copper doping and electron beam treatment. As-spun TiO2 nanofibers were fabricated by electrospinning a TiO2 sol, which obtained viscosity through a polyvinylpyrrolidone (PVP) matrix. Cu-doped TiO2 nanofibers with varying dopant concentrations were synthesized by adding copper salts. Then, the as-spun nanofibers were calcined for crystallization. To evaluate photocatalytic performance, a photodegradation test of methylene blue aqueous solution was performed for 6 h. Methylene blue concentration was measured over time using UV-Vis spectroscopy. The results showed that Cu doping at an appropriate concentration and electron-beam irradiation showed improved photocatalytic efficiency compared to bare TiO2 nanofibers. When the molar ratio of Cu/Ti was 0.05%, photodegradation rate was highest, which was 10.39% higher than that of bare TiO2. As a result of additional electron-beam treatment of this sample, photocatalytic efficiency improved up to 8.93% compared to samples without electron-beam treatment.

Design Optimization of Silicon-Based Optically Excited Terahertz Wave Modulation

The modulation of a terahertz (THz) wave on amplitude, phase and polarization is important for the application of THz technology, especially in the field of imaging, and is one of the current research hotspots. Silicon-based, optically excited THz modulator is a wavefront modulation technique with a simple, compact and reconfigurable optical path. It can realize the dynamic modulation of THz wavefronts by only changing the projected two-dimensional pattern, but it still suffers from the problems of lower modulation efficiency and slower modulation rates. In this article, the Drude model in combination with the multiple thin layers structure model and Fresnel matrix method is used to compare the modulation efficiencies of three modulation modes and more factors. The method is more accurate than the popular proposed method, especially when the thickness of the excited photoconductive layers reaches a few hundred microns. In comparing the three modes, namely transmission, ordinary reflection and total internal reflection, it is found the total internal reflection modulation mode has the best modulation efficiency. Further, under this mode, the effects of three factors, including the lifetime of photo-excited carriers, the wavelength of pump light and the frequency of THz wave, on the performance of THz modulator are analyzed. The simulation results show that the realization of total internal reflection using silicon prisms is a simple and effective method to improve the modulation efficiency of a silicon-based optically excited THz modulator, which provides references for the design of a photo-induced THz modulator.

Low-Temperature Growth of InGaAs Quantum Wells Using Migration-Enhanced Epitaxy.

The growth of InGaAs quantum wells (QWs) epitaxially on InP substrates is of great interest due to their wide application in optoelectronic devices. However, conventional molecular beam epitaxy requires substrate temperatures between 400 and 500 °C, which can lead to disorder scattering, dopant diffusion, and interface roughening, adversely affecting device performance. Lower growth temperatures enable the fabrication of high-speed optoelectronic devices by increasing arsenic antisite defects and reducing carrier lifetimes. This work investigates the low-temperature epitaxial growth of InAs/GaAs short-period superlattices as an ordered replacement for InGaAs quantum wells, using migration-enhanced epitaxy (MEE) with low growth temperatures down to 200-250 °C. The InAs/GaAs multi-quantum wells with InAlAs barriers using MEE grown at 230 °C show good single crystals with sharp interfaces, without mismatch dislocations found. The Raman results reveal that the MEE mode enables the growth of (InAs)4(GaAs)3/InAlAs QWs with excellent periodicity, effectively reducing alloy scattering. The room temperature (RT) photoluminescence (PL) measurement shows the strong PL responses with narrow peaks, revealing the good quality of the MEE-grown QWs. The RT electron mobility of the sample grown in low-temperature MEE mode is as high as 2100 cm2/V∗s. In addition, the photoexcited band-edge carrier lifetime was about 3.3 ps at RT. The high-quality superlattices obtained confirm MEE's effectiveness for enabling advanced III-V device structures at reduced temperatures. This promises improved performance for applications in areas such as high-speed transistors, terahertz imaging, and optical communications.

Migration-Enhanced Epitaxial Growth of InAs/GaAs Short-Period Superlattices for THz Generation

The low-temperature-grown InGaAs (LT-InGaAs) photoconductive antenna has received great attention for the development of highly compact and integrated cheap THz sources. However, the performance of the LT-InGaAs photoconductive antenna is limited by its low resistivity and mobility. The generated radiated power is much weaker compared to the low-temperature-grown GaAs-based photoconductive antennas. This is mainly caused by the low abundance of excess As in LT-InGaAs with the conventional growth mode, which inevitably gives rise to the formation of As precipitate and alloy scattering after annealing. In this paper, the migration-enhanced molecular beam epitaxy technique is developed to grow high-quality (InAs)m/(GaAs)n short-period superlattices with a sharp interface instead of InGaAs on InP substrate. The improved electron mobility and resistivity at room temperature (RT) are found to be 843 cm2/(V·s) and 1648 ohm/sq, respectively, for the (InAs)m/(GaAs)n short-period superlattice. The band-edge photo-excited carrier lifetime is determined to be ~1.2 ps at RT. The calculated photocurrent intensity, obtained by solving the Maxwell wave equation and the coupled drift–diffusion/Poisson equation using the finite element method, is in good agreement with previously reported results. This work may provide a new approach for the material growth towards high-performance THz photoconductive antennas with high radiation power.

SnS2/MoS2 van der Waals Heterostructure Photodetector with Ultrahigh Responsivity Realized by a Photogating Effect.

Photoresponsivity is a fundamental parameter used to quantify the ability of photoelectric conversion of a photodetector device. High-responsivity photodetectors are essential for numerous optoelectronic applications. Due to the strong light-matter interactions and the high carrier mobility, two-dimensional (2D) materials are promising candidates for the next-generation photodetectors. However, poor light absorption, lack of photoconductive gain, and the interfacial recombination lead to the relatively low responsivity of 2D photodetectors. The photogating effect, which extends the lifetime of photoexcited carriers, provides a simple approach to enhance responsivity in photodetector devices. Here, the O2 plasma treatment introduced surface traps on the SnS2 surface, leading to a gate-tunable photogating effect in SnS2/MoS2 heterojunctions. The heterojunction device exhibits an ultrahigh responsibility of up to 28 A/W. Moreover, the photodetector possesses a wide spectral photoresponse spanning from 300 to 1100 nm and a high specific detectivity (D*) of 4 × 1011 Jones under a 532 nm laser at VDS = 1 V. These results demonstrate that O2 plasma treatment is an efficient and simple avenue to achieve photogating effects, which can be employed to enhance the performance of van der Waals heterostructure photodetector devices and make them suitable for future integration into advanced electronic and optoelectronic systems.

PH-Dependent photocatalytic performance of faceted BiOBr semiconductor particles in degradation of dyes

Bismuth oxyhalides, such as bismuth-oxy-bromide (BiOBr), show high performance in photocatalytic oxidation of water pollutants. Process conditions, and in particular the pH of the solution, largely affect the photocatalytic efficacy, which is fundamentally poorly understood. We prepared {001} faceted bismuth-oxy-bromide (BiOBr), and determined by advanced AFM analysis that the surface charge of the {001} facet of BiOBr is slightly positive at acidic pH (pH 3) and significantly negative and increasing in negative surface charge in the order pH 6 < pH 9. Decomposition of MB or RhB by illumination of BiOBr is strongly favored by basic conditions (pH 9-10), as evident from discoloration experiments, and determination of the TOC as a function of time of illumination. Reference experiments show the pH dependent degradation profiles cannot be explained by differences in quantities of adsorption of the dye, but rather by the lifetime and/or quantity of BiOBr related photoexcited (surface) charge carriers (holes and electrons) – correlating with surface charge. Using MeOH and other scavengers, we show oxidation of MB or RhB is mainly induced by superoxide anions (•O2− radicals) at low pH and by holes or hydroxyl radicals at high pH – in agreement with surface charge induced band bending. This study provides novel understanding of the pH dependence of the rates of photocatalytic degradation of dyes using BiOBr photocatalysts.

Efficient charge separation and improved photoelectric properties of GaN/WS2/MoS2 heterojunction: A molecular dynamics simulations

Utilizing the stacking of two-dimensional (2D) materials to fabricate heterojunction represents an exceedingly effective approach for designing high-performance optoelectronic devices. In this paper, the GaN/WS2/MoS2 heterojunction was systematically studied using DFT calculations. The interface effect caused the effective separation of photo-excited carriers in the GaN/WS2/MoS2 heterojunction by inducing a stepwise transfer of the carriers, forming a build-in electric field. Due to the decrease in bandgap, the heterojunction exhibited enhanced light absorption ability across the entire spectral region. Especially, the carrier recombination time reached the microsecond level, greatly extending the lifetime of photo-excited carriers and effectively improving the energy conversion performance of photodetectors. Moreover, the augmentation of tensile strain enhances both the self-powering capacity and the near-infrared light detection capability of the GaN/WS2/MoS2 heterojunction. The exceptional performances exhibited by the GaN/WS2/MoS2 heterojunction make it a highly up-and-coming candidate for optoelectronics application.

Photo-excited charge carrier lifetime enhanced by slow cation molecular dynamics in lead iodide perovskite FAPbI3

Using muon spin relaxation measurements on formamidinium lead iodide [FAPbI3, where FA denotes HC(NH2)2], we show that, among the five structurally distinct phases of FAPbI3 exhibited through two different temperature hysteresis, the reorientation motion of FA molecules is quasi-static below ≈50 K over the time scale of 10−6 s in the low-temperature (LT) hexagonal (Hex-LT, &amp;lt;160 K) phase, which has a relatively longer photo-excited charge carrier lifetime (τc∼10−6 s). In contrast, a sharp increase in the FA molecular motion was found above ≈50 K in the Hex-LT phase, LT-tetragonal phase (Tet-LT, &amp;lt;140 K), the high-temperature (HT) hexagonal phase (Hex-HT, 160–380 K), and the HT-tetragonal phase (Tet-HT, 140–280 K), where τc decreases with increasing temperature. More interestingly, the reorientation motion is further promoted in the cubic phase at higher temperatures (&amp;gt;380/280 K), while τc is recovered to comparable or larger than that of the LT phases. These results indicate that there are two factors that determine τc, one related to the local reorientation of cationic molecules that is not unencumbered by phonons and the other to the high symmetry of the bulk crystal structure.

Facile route of heterostructure CeO2–CuO nanocomposite as an efficient electron transport material for perovskite solar cells

Cerium copper metal nanostructures have received extensive attention as promising electrode materials for energy storage applications due to its attractive structure, and good conductivity. Herein, CeO2–CuO nanocomposite was prepared via chemical method. The crystal structure, dielectric, and magnetic properties of the samples were characterized using by different techniques. The morphological properties of samples were inspected by field emission scanning electron microscopy (FE‒SEM) and high-resolution transmission electron microcopy (HR‒TEM) analysis implied an agglomerated with nanorod structure. The sample surface roughness and morphology were inspected using atomic force microscopy (AFM). Electron paramagnetic resonance (EPR) spectroscopy result reveals the oxygen insufficiency in the material. The variation of oxygen vacancies concentration is consistent with the changes of the saturation magnetization for the sample. Dielectric constant and dielectric losses were studied with respect to the temperature from range from 150 to 350 °C. The electrochemical study of CeO2–CuO nanocomposite shows clear oxidation and reduction peaks with covering wide potential range. In this present paper, first time we have demonstrated that the CeO2–CuO composite as an electron transport material (ETM) with copper (I) thiocyanate (CuSCN) as hole transport material (HTM) for the perovskite solar cells device fabrication. To understand the properties of perovskite like structural, optical, and morphological extensive characterizations such as XRD, UV–visible spectroscopy, and FE-SEM, was performed. For the first time, the CeO2–CuO was used as anode material for preparation low-temperature processing perovskite solar cells, results the power conversion efficiency (PCE) of 10.58% was achieved. The improvement in the device performance for the nanocomposite compared to the pure CeO2, due to unique properties of CeO2–CuO, including high hole mobility, good energy level alignment with CH3NH3PbI3 and longer life time of photo-excited carriers for facilitating the developments of industrial-scale perovskite solar cells.

Lifetime of photoexcited carriers in space-controlled Si nanopillar/SiGe composite films investigated by a laser heterodyne photothermal displacement method

Thermal management has become more critical as semiconductor devices are miniaturized. In metal–oxide–semiconductor field-effect transistors, the problem is the reduction in electron mobility in the channel layer owing to the temperature rise caused by heat generation near the channel-drain region. Focusing on the mean free paths of phonons and electrons in Si, nanostructures of a few 10 nm may only hinder heat propagation without affecting electron transportation. Therefore, inserting nanostructures into the channel layer may prevent a temperature rise and maintain a higher electron mobility. To discuss the relationship between the spacing between the nanopillars (NPs) and the heat generation and carrier behavior of the Si-NP/SiGe composite film, samples with NP spacings of 13, 27, or 47 nm were prepared. We previously confirmed that the thermal conductivity of the Si-NP/SiGe composite film decreased as NP spacing narrowed. The NPs scattered phonon propagation and suppressed heat propagation. However, carrier transport properties such as electrical conductivity, carrier mobility, and carrier lifetime have never been discussed. The laser heterodyne photothermal displacement method was used to examine the effect of nanostructures on carrier mobility and carrier lifetime of Si-NP/SiGe composite films. We observed that the carrier lifetime became longer when the NP spacing was comparable to the electron mean-free path of approximately 27 nm.

Excitation-Wavelength-Dependent Charge-Carrier Lifetime in Hematite: An Insight from Nonadiabatic Molecular Dynamics.

Experiments have reported that the photoexcited carrier lifetime in α-Fe2O3 has a significant excitation-wavelength dependence but leave the physical mechanism unresolved. In this work, we rationalize the puzzling excitation-wavelength dependence of the photoexcited carrier dynamics in Fe2O3 by performing nonadiabatic molecular dynamics simulation based on the strongly constrained and appropriately normed functional, which accurately describes the electronic structure of Fe2O3. Photogenerated electrons with lower-energy excitation relax fast in the t2g conduction band within about 100 fs, while the photogenerated electrons with higher-energy excitation undergo first a slower interband relaxation from the eg lower state to the t2g upper state on a time scale of 135 ps, followed by the much faster t2g intraband relaxation. This study provides insight into the experimentally reported excitation-wavelength dependence of the carrier lifetime in Fe2O3 and a reference for regulating photogenerated carrier dynamics in transition-metal oxides through the light excitation wavelength.

Ultrafast Optical Nanoscopy of Carrier Dynamics in Silicon Nanowires.

Carrier distribution and dynamics in semiconductor materials often govern their physical properties that are critical to functionalities and performance in industrial applications. The continued miniaturization of electronic and photonic devices calls for tools to probe carrier behavior in semiconductors simultaneously at the picosecond time and nanometer length scales. Here, we report pump-probe optical nanoscopy in the visible-near-infrared spectral region to characterize the carrier dynamics in silicon nanostructures. By coupling experiments with the point-dipole model, we resolve the size-dependent photoexcited carrier lifetime in individual silicon nanowires. We further demonstrate local carrier decay time mapping in silicon nanostructures with a sub-50 nm spatial resolution. Our study enables the nanoimaging of ultrafast carrier kinetics, which will find promising applications in the future design of a broad range of electronic, photonic, and optoelectronic devices.

Simultaneous Characterization of Optical, Electronic, and Thermal Properties of Perovskite Single Crystals Using a Photoacoustic Technique

Metal halide perovskite possesses many excellent properties beneficial to its potential applications in optoelectronics and pyroelectricity. Surface recombination velocity, electronic diffusivity, and excess carrier lifetime accounting for the photoexcited carrier recombination and electronic transport features are key for improving the performance of perovskite-based optoelectronic devices. Meanwhile, the thermal conductivity and thermal diffusivity in halide perovskite have been paid limited attention despite their potential practical applications such as heat management and thermoelectric materials. To date, lots of techniques have been developed to extract these physical properties, while very few of them can effectively and nondestructively receive the results. The photoacoustic (PA) technique based on photothermal conversion is a powerful method to study the optical, electronic, and thermal properties of various materials, especially semiconductor materials. Optical absorption spectrum, surface recombination velocity, electronic diffusivity, photoexcited carrier lifetime, and thermal diffusivity can be obtained simultaneously without the destruction and contact of the samples. Here, for the first time, we utilized the PA technique in the perovskite single crystal. Optical absorption of MAPbBr3 and MAPbI3 (MA = methylammonium) single crystals was investigated under a reflection detection configuration (RDC), and the electronic and thermal properties were measured under a transmission detection configuration (TDC). Comparing the results with previous reports and other characterizations, the PA technique has been verified to be an efficient and convenient method to study the optical, electronic, and thermal properties of perovskite single crystals.

Construction of Direct Z-Scheme SnS2 Quantum Dots/Conjugated Polyimide with Superior Photocarrier Separation for Enhanced Photocatalytic Performances.

In this study, a novel direct Z-scheme SnS2 quantum dots/sulfur-doped polyimide (SQDs/SPI) photocatalyst was firstly fabricated by an in situ crystallization growth of SnS2 quantum dots on sulfur-doped polyimide through a facile hydrothermal method. The photocatalytic hydrogen production activity of 5SQDs/SPI samples reached 3526 μmoL g-1 in the coexistence of triethanolamine and methanol used as hole sacrificial agents, which is about 13 times higher than that of SPI under the same conditions and 42 times higher than that of SPI only as a hole sacrificial agent. The improvement can be related to the direct Z-scheme charge transfer in the tight interface between SQDs and SPI, which promoted rapid separation and significantly prolonged the lifetime of photoexcited carriers. The Z-scheme charge transfer mechanism was proposed. This discovery comes up with a new strategy for the development of an efficient, environmentally friendly, and sustainable sulfide quantum dots/polymer non-noble metal photocatalyst.

Surface Plasmon-Induced Hot Carriers: Generation, Detection, and Applications.

ConspectusDuring surface plasmon-mediated light-matter interactions, external energies on plasmonic metal nanostructures undergo energy dissipation via elastic e-e scattering, radiative luminescence, and nonradiative processes such as thermal relaxation (phonon) and electronic excitation (electron-hole pairs). In this process, surface plasmon decays dominantly through nonradiative recombination when the metal is smaller than 25 nm, forming hot carriers, including hot electrons and hot holes, with high kinetic energy of 1-3 eV. Although the ultrafast dynamics of hot carriers are on time scales ranging from femtoseconds to picoseconds, these fast-disappearing hot carriers can be collected as the steady-state photocurrent or chemicurrent by adopting the metal-semiconductor (M-S)-based platform for detecting hot carrier flow. Plasmonic hot carriers, especially as they convert to an electrochemical signal, are a promising topic, and their energy conversion mechanisms are being actively studied in the fields of renewable energy, optoelectronics, and photocatalysis. Recent studies have demonstrated that these hot carriers can both improve the performance of solar energy conversion and control the catalytic activity or selectivity by directly participating in the photoelectrochemical (PEC) reaction.In this Account, we describe the inherent relationship between hot carriers and surface plasmon as well as what role hot carriers play throughout the catalytic reaction. The recent experimental work and the theoretical analysis of in situ hot carrier generation on Au nanostructures were conducted with photoconductive atomic force microscopy and finite-difference time-domain (FDTD) simulations, respectively. We highlight the recent nanoscale visualization of hot carrier flow occurring through light-matter interactions and that the localized surface plasmon field surrounding the Au nanostructure leads to boosted hot carrier generation. In addition, we highlight the recent demonstration that plasmonic hot carriers prolong the lifetime of photoexcited carriers in the MAPbI3/Au/TiO2 hybrid nanodiode by the synergistic effect between plasmonic Au and perovskites. From this work, the solar-to-electron conversion performance of this nanodiode significantly increases due to the amplification of light absorption, which helps to design hybrid platforms for efficient hot carrier photovoltaics. We discuss the application of surface plasmon-driven hot electron generation, including hot electron-based photovoltaic devices and photocatalysts. We highlight the recent photoelectrochemical measurements on the Au/p-GaN heterostructures that are controlled by participating plasmonic hot carriers in the water splitting reaction. Furthermore, controlling the flow of both hot electrons and holes by developing hybrid platform configurations for hot carrier applications has promising opportunities for regulating the catalytic activities of hot carrier-based photocatalysis and improving the photoconversion efficiency of hot carrier-based optoelectronic devices.

ZnSe and CdS Co-Sensitized TiO2 Nanorod Arrays as Photoanodes for Bias-Free Solar Hydrogen Evolution.

The efficient charge separation and surface state reactions are significant in enhancing the efficiency of photoelectrochemical hydrogen evolution. Herein, we report a ternary heterostructure consisting of CdS/ZnSe sensitized TiO2 nanorod as a photoanode. The heterojunction photoanode considerably widens the photon absorption spectral range and thereby enhances the photocurrent density up to 2 mA/cm2 at 1.23 V versus RHE which is 10 times higher than pristine TiO2 photoanode. The photoelectrochemical results demonstrate a high photocurrent density of 2 mA/cm2 with a photon-to-current conversion efficiency of 1.5 % at a very low applied bias (0.2 V vs RHE). The improved PEC performances of the multidimensional hybrid photoanode could be ascribed to the efficient visible-light absorption of ZnSe and CdS nanocrystals decorated on the surface of 1D TiO2 . The rapid electron-transfer properties owing to higher carrier density, low carrier transport resistance, and an extended lifetime of photoexcited carriers in the multidimensional ZnSe/CdS/TiO2 heterostructure with suppressed surface charge recombination are responsible for enhanced hydrogen evolution activities.