Reduced Charge Recombination Research Articles

Improved photocatalytic degradation of malachite green with a novel composite β-bihydroxycobalt phthalocyanine/Cu-BTC

Abstract In this work, a novel MOF (metal organic framework) based composite of β-BCoPc/Cu-BTC is fabricated by immobilizing β-aryloxy phthalocyanine cobalt (β-BCoPc) on Cu-BTC (benzenetricarboxylic acid-Cu) via a facile impregnation approach. After a systematic characterization via X-ray diffraction, X-ray photoelectron spectroscopy, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption isotherms, the above-synthesized catalyst is for the first time applied to photocatalytically decompose refractory malachite green (MG) dye pollutant under UV light irradiation. In comparison with that of the β-BCoPc or Cu-BTC monomers, the synthesized β-BCoPc/Cu-BTC composite shows a significantly enhanced photocatalytic degradation performance of MG with a best degradation efficiency up to 90.12 %, which can easily be attributed to the synergistic effect between the Cu-BTC and β-BCoPc effectively improving light utilization efficiency, accelerating charge transportation and reducing charge recombination due to the desirable properties such as the conjugacy of the MOFs skeleton, the positive catalytic activity of central ion and large specific surface area, etc. In conclusion, the present work provides an effective and novel strategy via preparing MOF-based composite catalyst to realize the photocatalytic degradation of MG.

Facet-dependent spatial charge separation with rational cocatalyst deposition on BiVO4

Rational assembly of cocatalyst on the photocatalyst with exposed functional crystal facets has been demonstrated to be viable in enhancing the photocatalytic activity. However, greater attention is paid to the property of the loaded cocatalyst while the effect of varied functional facet exposure is relatively less discussed. Herein, dual-faceted BiVO4 with well-defined {010} and {110} facets but with varied {010}/{110} exposure extent ratios are coupled with CoOx which is known as a cocatalyst for water oxidation. The enhancement induced by the cocatalyst loading depends on both its deposit location and the ratio of {010}/{110} facet exposure. When selectively deposited on oxidation {110} facet, CoOx generates over two-fold enhancement on BiVO4 in photocatalytic oxygen evolution as compared to its randomly deposited analogue. Meanwhile, the {010}-dominant BiVO4 is more obviously benefited from the cocatalyst loading to both photocatalytic water oxidation and hydrogen peroxide generation reactions with respect to the {110}-dominant BiVO4. Further investigation reveals that CoOx functions more effectively in PL quenching and generating greater band bending on {010}-dominant BiVO4, substantiating the better enhancement in reducing charge recombination and forming larger space charge region width for charge separation, which deliver greater photocatalytic activity enhancement on {010}-dominant BiVO4.

Plasmon assisted optical absorption and reduced charge recombination for improved device performance in polymer solar cell

Silver and Calcium (Ag:Ca) bi-metallic nano-partices have been successfully synthesized using a chemical reduction processes. The nano-partices were intended to be used in the solar absorber layer of thin film organic solar cell (TFOSC) to assist in improving optical absorption and charge transport processes in polymers blend medium. The nanocomposite (Ag:Ca) is expected to exhibit local surface plasmon resonance (LSPR) and far-field scattering from the interaction with the incident photons. The absorber layer of TFOSC, in this investigation, is prepared from the mixture of poly-(3-hexylthiophene) (P3HT): [6,6]-phenyl C61 butyric acid methyl ester (PC61BM). Devices were fabricated at various concentration of metal nano-particles in the solar absorber layer, as 1%, 3%, and 5% by weight, to be able to determine the optimum concentration of the dopant. Hence, the experimental evidences clearly showed that performance of the solar cell is dependent on the concertation of the metal nano-particles. Consequently, the power conversion efficiency (PCE) value has increased by 75% with a remarkable improvement in device fill factor of 53.4% at an optimum doping level of 3%. The optical and morphological properties of the synthesized nano-particles are well presented and discussed in terms of the data collected using transmission and scanning electron microscopy (TEM & SEM) and other complimentary methods.

Enhancing the photovoltaic properties of SnS-Based solar cells by crystallographic orientation engineering

Tin monosulfide (SnS) is a promising light-harvesting material for solar cell applications, owing to its potential for large-scale production, cost-effectiveness, eco-friendly source materials, and long-term stability. However, SnS crystallizes in an orthorhombic structure, which results in a highly anisotropic charge transport behavior. Tailoring the crystallographic orientation of the SnS absorber layer plays a critical role in the enhancement of the transfer of charge carriers and the power conversion efficiency (PCE). By controlling the substrate tilting angle and temperature ramp rate in vapor transport deposition, the crystal growth orientation was tuned to a preferred direction which significantly suppressed the unfavorable (040) crystallographic plane. Through the combination of these two approaches, the PCE could be increased from 0.11% to 2%. The effect of the tilting angle was numerically simulated to investigate its role in controlling the film uniformity and directing the film growth. In addition, the correlation between the texture coefficient of the (040) plane and the charge transport properties was determined by a combination of analytical methods such as device performance studies, electrochemical impedance spectroscopy, along with transient photovoltage, space-charge-limited current, and dark current measurements. These techniques were blended together to prove that the marked improvement in PCE can be ascribed to a reduced charge recombination (in both SnS bulk and interfaces) and an enhanced hole mobility.

Uncovering synergistic effect of chloride additives for efficient quasi-2D perovskite solar cells

• MACl and PbCl 2 binary additives form MAPbCl 3 intermediate phase. • Perovskite crystallization is retarded and volatilization of MACl is prevented. • Such a synergistic effect leads to high-quality Q-2D perovskite films. • Charge recombination is suppressed and charge extraction efficiency is enhanced. • The champion PCE of 18.67% is one of the highest PCE for Q-2D RP PSCs with n ≤ 4. Methylammonium chloride (MACl) and lead chloride (PbCl 2 ) are commonly used for improving perovskite film quality. However, the rapid release of volatile MACl would lead to low-quality perovskite films with pinholes and defects. Here, we report a strategy of employing MACl&PbCl 2 binary additives together to prepare high-quality quasi-two-dimensional (Q-2D) Ruddlesden–Popper (RP) perovskite films. We found that MAPbCl 3 intermediate phase is formed via a reaction between MACl and PbCl 2 , which suppresses the fast volatilization of MACl, resulting in a compact and pinhole-free perovskite film with large grains. Moreover, the trap states are passivated via the incorporation of Cl – into the Q-2D perovskite crystals along with the addition of PbCl 2 , leading to a reduced charge recombination loss and an improved charge extraction. A remarkable power conversion efficiency (PCE) of 18.67% is achieved in such Q-2D RP PSCs, one of the highest PCE values among the low-dimensional RP PSCs with n ≤ 4. The environmental stability of the devices is also significantly enhanced. Our results provide an effective strategy by using chloride based additives for fabricating high-quality low-dimensional RP perovskite films for efficient solar cells.

Ceria-doped SnO2 nanocubes for solar light-driven photocatalytic hydrogen production.

The photocatalytic generation of hydrogen via solar energy using metal oxide semiconductor catalysts is a clean and renewable process which has the potential of solving the current energy nexus. SnO2 is one such well-studied and established photocatalyst currently in practice but is only ultraviolet-light active which accounts for only 4% of the total incoming solar energy. The current study focuses on bringing this SnO2 into the visible range using ceria as a dopant. Sol-gel and combustion methods were employed for synthesis and the as-synthesized catalysts were characterized using XRD, BET, UV diffuse reflectance spectra, PL spectra, and SEM micrographs. A unique cuboid type morphology was observed in 6% ceria-doped SnO2 which provided more active sites for light absorption and thus reported a remarkable hydrogen production rate of 1.978mmol/h under sunlight which was almost 346 times that of pure SnO2 (5.71µmol/h). Photoluminescence spectra of ceria-doped SnO2 showed lower peak positions as compared to the pure SnO2 indicating a reduction in charge recombination and an increase in the life time of the active species which explains the enhanced hydrogen production rates. The recyclability study of the catalysts showed that the hydrogen amount produced in the fifth recycle was nearly 80% as the first cycle showing that the catalyst can be used very effectively for more than five cycles without compromising on the yield.

Energy Band Engineering by CdTe/Si Codoped TiO2 Nanoarrays for Enhanced Photoelectrochemical Water Splitting

The wide bandgap energy of TiO2 limited its photocatalytic activity to UV light. To meet this challenge, TiO2 nanorods were doped with Si atoms and decorated by CdTe QDs to enhance the electronic structure, broaden the absorption domain, and improve photoelectrochemical (PEC) water splitting. Incorporation of Si atoms in the TiO2 structure effectively enhanced the transfer of charge carriers and the wettability of the surface in the Si:TiO2 electrode and made it an effective platform for solar-assisted water splitting. Moreover, the IPCE results prove that CdTe QDs with high absorption coefficient and photon upconversion spread the photoresponse of CdTe/Si:TiO2 to visible light with an improved photocurrent density of 4.3 mA cm–2 at the potential of 1.23 V vs RHE. The excellent increase of 12.5 times in PEC activity of CdTe/Si:TiO2 electrode as compared to unmodified TiO2 nanoarrays and its low overpotential are due to the faster electron transfer kinetics, enhanced charge carriers density (Nd), and reduced charge recombination rate. The photocurrent stability of CdTe/Si:TiO2 in numerous on/off cycles and its long-term durability with a photocurrent decay of about 5% over 10 h show its high photocorrosion resistance. The current study signifies that CdTe/Si:TiO2 is a suitable and highly efficient photoelectrocatalyst for water splitting.

Characteristics of dual acceptor ternary organic photodetectors based on P3HT:PC61BM:IEICO-4F

A new method for realizing the response broadening of organic photodetectors (OPDs) using non-fullerene acceptor IEICO-4F doping has been proposed in this paper. It was found that when the mass ratio of P3HT:IEICO-4F:PC61BM in the active layer was 10:2:8, the spectral response range of OPDs was extended to 400–900 nm. The responsivity (R) and external quantum efficiency (EQE) of ternary OPDs reached 230, 263, 199 mA·W–1 and 46%, 62%, 54% under 630, 530, 460 nm illumination and –1.5 V bias, respectively. The detectivity (D*) reached 1012 Jones. The results showed that the addition of IEICO-4F increased the exciton dissociation interface and improved the dissociation rate of the active layer, thus improving the photocurrent of the device. In addition, the addition of IEICO-4F promoted the crystallization of the film, reduced charge recombination, and thereby reduced the dark current of the device.

Significantly improved photocatalytic activity of the SnO2/BiFeO3 heterojunction for pollutant degradation and mechanism

Herein, motivated with narrow/wide-bandgap heterojunction materials as one of the perfect solutions, we separately synthesized BiFeO3 (BFO) and SnO2 nanoparticles; then coupled them in various weight percentages to obtain nanocomposites with efficient contacts for visible light 2,4-DCP and RhB degradation and effectively reduced charge recombination. The material of interest, i.e., with six weight percentage coupling of SnO2 (i.e., 6SO/94BFO), endorsed superior photoactivity for 2,4-DCP and RhB degradation. In addition, under the visible light irradiation, this photocatalyst degraded 87.2% of RhB and 65.1% of 2,4-DCP in 2h, which compared to pristine BiFeO3 nanoparticles are about 2.6- and 2.7-times enhancements, respectively. The photoluminescence spectroscopy and mechanism model showed a substantial interface between BiFeO3 and SnO2 and unfeasible electron-holes recombination. The electrons and holes are entirely utilized to produce superoxides and •OH radicals, respectively, predicting enhanced visible-light photodegradation. Overall, this work offers novel narrow/wide-bandgap heterojunction nanocomposites as feasible aspirants for pollution control and effective visible light photodegradation of chlorinated compounds.

Enhancing the Performance of Small-Molecule Organic Solar Cells via Fused-Ring Design.

Organic solar cells (OSCs) as the promising green energy technology have drawn much attention in the last two decades. In comparison to polymer solar cells, small-molecule organic solar cells (SMOSCs) have the advantages of precise chemical structure and molecular weight, purification feasibility, batch reproducibility, etc. Despite of the recent advances in molecular design, the efficiencies of SMOSCs are still lagging behind those of polymer-based OSCs. In this work, a new small-molecule donor (SMD) with a fused-ring-connected bridge denoted F-MD has been designed and synthesized. When F-MD was applied into SMOSCs, the F-MD:N3 blends exhibited a power conversion efficiency (PCE) of over 13%, which is much higher than that of the linear π-bridged molecule L-MD based devices (8.12%). Further studies revealed that the fused-ring design promoted the planarity of the molecular conformation and facilitated charge transport in OSCs. More importantly, this strategy also lowered the crystallinity and self-aggregation of the films, and hence optimized the microstructure and phase separation in the corresponding blends. Thereby, the F-MD-based blends have been evidenced to have better exciton dissociation and reduced charge recombination in comparison with the L-MD counterparts, explaining the enhanced PCEs. Our work demonstrates that the fused-ring π-bridge strategy in small-molecule-donor design is an effective pathway to promote the efficiency of SMOSCs as well as enhance the diversity of SMD materials.

Engineered Cathode Buffer Layers for Highly Efficient Organic Solar Cells: A Review

AbstractThis article presents an in‐depth insight into the most efficient cathode buffer layers (CBLs) in conventional and inverted organic solar cells (OSCs). The CBL can play a critical role in improving the short circuit current density (Jsc) and fill factor (FF) of the devices by minimizing the contact resistance and reducing charge recombination at electrode/photoactive layer interface, resulting in the efficient extraction of charge carriers and therefore improving the power conversion efficiency (PCE). This review explores CBL with respect to its effect on the physics of a device and electronic processes at the interface of CBL/photoactive layer and its impact on the overall performance of OSCs. Besides this, the role of CBL, its chemical composition, morphology, thickness, dopants, deposition conditions, etc., and their corresponding effects on the device performance of both conventional and inverted OSCs are discussed in detail. Finally, CBLs that provide the best performance are summarized and their chemical structures are discussed. This article will benefit the researchers working in the domain of OSCs by providing an understanding of the CBL layers, along with various interfacial processes.

New Medium Bandgap Donor D-A1 -D-A2 Type Copolymers Based on Anthra[1,2-b: 4,3-b":6,7-c"'] Trithiophene-8,12-dione Groups for High-Efficient Non-Fullerene Polymer Solar Cells.

A new acceptor unit anthra[1,2-b: 4,3-b': 6,7-c'']trithiophene-8,12-dione (А3Т) (A2) is synthesized and used to design D-A1 -D-A2 medium bandgap donor copolymers with same thiophene (D) and A2 units but different A1, i.e., fluorinated benzothiadiazole (F-BTz) and benzothiadiazole (BTz) denoted as P130 and P131, respectively. Their detailed optical and electrochemical properties are examined. The copolymers show good solubility in common organic solvents, broad absorption in the visible spectral region from 300 to 700 nm, and deeper HOMO levels of -5.45 and -5.34 eV for P130 and P131, respectively. Finally, an optimized polymer solar cell (PSC) based on P131 as the donor and narrow bandgap non-fullerene small molecule acceptor Y6 demonstrated a power conversion efficiency (PCE) of >11.13%. To further improve the efficiency of the non-fullerene PSC, the P130 is optimized by introducing a fluorine atom into the BTz unit, F-BTz acceptor unit, and PCE PSC based on P130: Y6 active layer increased to >15.28%, which is higher than that for the non-fluorinated analog P131:Y6. The increase in the PCE for former PSC is attributed to the more crystalline nature and compact π-π stacking distance, leading to more balanced charge transport and reduced charge recombination. These remarkable results demonstrate that A3T-based copolymer P130 with F-BTz as the second acceptor is a promising donor material for high-performance PSCs.

Crystal Facet Engineering of TiO2 Nanostructures for Enhancing Photoelectrochemical Water Splitting with BiVO4 Nanodots

HighlightsTwo types of BiVO4/TiO2 heterostructure photoanodes comprising TiO2 nanorods (NRs) and TiO2 nanoflowers (NFs) with different (001) and (110) crystal facets, respectively, were designed.The higher photoactivity of BiVO4/TiO2 NFs than BiVO4/TiO2 NRs was attributed to the improvement of charge separation by the TiO2 NFs.The formation of type II band alignment between BiVO4 nanodots and TiO2 NFs expedited electron transport and reduced charge recombination.

Rational design of ZnO-zeolite imidazole hybrid nanoparticles with reduced charge recombination for enhanced photocatalysis

Semiconducting zinc oxide nanoparticles (ZnO NPs) hold great potential as photocatalysts in wastewater treatment because of their favorable bandgap and cost-effectiveness. Unfortunately, ZnO NPs usually show rapid charge recombination that limits their photocatalytic efficacy significantly. Herein, we report a facile way of modifying ZnO NPs with zeolite imidazole framework-8 (ZIF8). A synergy between the two components may tackle the drawback of fast charge recombination for pristine ZnO NPs. Improved performance of photocatalytic degradation of methylene blue (MB) is confirmed by comparing with pristine ZnO and ZIF8 as the catalysts. The ZIF8 in the composite serves as a trap for photogenerated electrons, thus reducing the rate of charge recombination to enhance the photocatalysis rate. In addition, the hybridization process suppresses the aggregation of ZnO NPs, providing a large surface area and a greater number of active sites. Moreover, a small shift in the absorption band of ZnO@ZIF8 (10) NPs towards higher wavelength, also witnessed a little contribution towards enhanced photocatalytic properties. Mechanistic studies of the photocatalytic process of MB using ZnO@ZIF8 NPs catalyst reveal that hydroxyl radicals are the major reactive oxygen species. The facile hybridization of ZnO with ZIF8 provides a strategy for developing new photocatalysts with wide application potential.

Quaternary Organic Solar Cells Enable Suppressed Energy Loss

Multi‐component organic solar cells (OSCs) composing of more than two donor and acceptor materials have attracted increasing attention, due to the possibilities to further mitigate voltage loss (ΔVoc) for the gain of open‐circuit voltage (Voc). However, the control of phase morphology in multi‐component blend systems that critically impacts ΔVoc and the ultimate power conversion efficiency (PCE) is still a challenge. Here, we report a quaternary blend‐based strategy for non‐fullerene OSCs by using two polymer donors (PM6 and L20) along with acceptors of a non‐fullerene (Y6) and PC71BM, leading to concurrent improvements of the Voc, device fill factor and eventual PCE. The quaternary OSC exhibits the advantages of a higher charge collection efficiency, expedited charge carrier sweep‐out, and reduced charge recombination losses. The suppression on ΔVoc is attributed to the reduced radiative recombination loss below the bandgap (0.143 V) and non‐radiative voltage loss (0.216 V). These properties are linked to synergies of modified energetics and film morphology of the quaternary blends. This work demonstrates that incorporating suitable donor and acceptor guest molecules to organic binary blend systems is a highly viable approach for lowering the energy loss in organic bulk heterojunctions towards the boost of photovoltaic performance for realistic energy conversion applications.

Effect of TiO2 surface treatment on electron transfer in dye-sensitized solar cells

Defect states in the TiO2 nanoparticles can cause severe charge recombination and poor electron-transport efficiency when used as a photoanode in dye-sensitized solar cells (DSSCs). Herein, we report a simple and practical way to passivate the surface defects of TiO2 through hydrothermal treating with acetic acid and H2SO4, introducing a high percentage of 101 facets and sulfonic acid functional groups on the TiO2 surface. A high efficiency of 8.12% has been achieved, which is 14% higher than that of untreated TiO2 under the same condition. EIS results prove that the multiacid-treated TiO2 can promote electron transport and reduce charge recombination at the interface of the TiO2 and electrolyte. This work provides an efficient approach to engineer the electron-transport pathway in DSSCs.

CO Adsorbate Promotes Polaron Photoactivity on the Reduced Rutile TiO2(110) Surface.

Polarons play a major role in determining the chemical properties of transition-metal oxides. Recent experiments show that adsorbates can attract inner polarons to surface sites. These findings require an atomistic understanding of the adsorbate influence on polaron dynamics and lifetime. We consider reduced rutile TiO2(110) with an oxygen vacancy as a prototypical surface and a CO molecule as a classic probe and perform ab initio adiabatic molecular dynamics, time-domain density functional theory, and nonadiabatic molecular dynamics simulations. The simulations show that subsurface polarons have little influence on CO adsorption and CO can desorb easily. On the contrary, surface polarons strongly enhance CO adsorption. At the same time, the adsorbed CO attracts polarons to the surface, allowing them to participate in catalytic processes with CO. The CO interaction with polarons changes their orbital origin, suppresses polaron hopping, and stabilizes them at surface sites. Partial delocalization of polarons onto CO decouples them from free holes, decreasing the nonadiabatic coupling and shortening the quantum coherence time, thereby reducing charge recombination. The calculations demonstrate that CO prefers to adsorb at the next-nearest-neighbor five-coordinated Ti3+ surface electron polaron sites. The reported results provide a fundamental understanding of the influence of electron polarons on the initial stage of reactant adsorption and the effect of the adsorbate–polaron interaction on the polaron dynamics and lifetime. The study demonstrates how charge and polaron properties can be controlled by adsorbed species, allowing one to design high-performance transition-metal oxide catalysts.

2D-Bi4NbO8Cl nanosheet for efficient photocatalytic degradation of tetracycline in synthetic and real wastewater under visible-light: Influencing factors, mechanism and degradation pathway

A 2D-Bi4NbO8Cl nanosheet (BNOCF) photocatalyst was fabricated using molten salt or flux method and was employed to degrade tetracycline (TCH) under visible light irradiation. The as-synthesized photocatalyst was characterized by a wide range of studies and compared with bulk-Bi4NbO8Cl (BNOCS). The BNOCF photocatalyst displayed 2.2 times higher degradation efficiency as compared to BNOCS. The enhanced efficiency could be attributed to the 2D architecture, with increased surface area and reduced charge recombination rate. The effect of various parameters was studied, and the optimal photocatalytic efficiency (96.5%) of BNOCF was obtained at a dosage of 1 g L−1, TCH concentration of 10 mg L−1, pH 4.4, and the light intensity of 10 mW cm−2. The effects of coexisting inorganic salts and real wastewater sources were also studied. A detailed study showed that a complex between BNOCF and TCH led to TCH degradation by inducing strong visible-light absorption. The radical trapping experiments showed that •O2− was primarily responsible for the degradation of TCH. Based on these findings, the photocatalytic mechanism was proposed. The inorganic ions like CO32-, Cl- and SO42- were found to hinder the degradation efficiency of BNOCF slightly. Excellent degradation efficiency (95.9%) was achieved towards TCH present in a real wastewater sample. The catalyst efficiently mineralized 34.6% TCH in 1 h, and after four recycling tests, was found quite stable. The intermediate products of TCH degradation over BNOCF were detected, and plausible degradation pathways were proposed. This study proves that BNOCF possesses tremendous potential as a visible-light-reactive photocatalyst in prospective wastewater treatment applications.

Hydrothermal synthesis of CuO/g-C3N4 nanosheets for visible-light driven photodegradation of methylene blue

In this article, we synthesized pure CuO, and a g-C3N4/CuO heterostructure using a hydrothermal technique. The synthesized samples were evaluated using different analytical techniques, demonstrating that the addition of g-C3N4 substantially altered the crystallinity, energy bandgap, particle size, and morphology. The interfacial contact between g-C3N4 and CuO, as well as the formation of heterostructure between them, was confirmed by XPS and TEM. We found that pure CuO, g-C3N4 and g-C3N4/CuO heterostructure has a bandgap of 1.40 eV, 2.70 eV and 1.30 eV respectively. The effectiveness of photodegradation of MB dye was observed to be 78%, 72% and 94% for pure CuO, g-C3N4 and g-C3N4/CuO after 100 min of visible light illumination. All samples exhibit pseudo-first-order kinetics for photodegradation of MB dye with good recyclability up to five cycles. The higher photodegradation efficiency of g-C3N4/CuO is may be attributed to its lower bandgap energy, enhanced charge transport, and reduced charge recombination than pure CuO and g-C3N4. Hence, designing g-C3N4/CuO heterostructure can be a potential approach towards wastewater treatment.

Holistically modulating charge recombination via trisiloxane surface treatment for efficient dye-sensitized solar cells

Dye-sensitized solar cells (DSSCs) with TiO2 as electron transport layer (ETL) demonstrate great potential in the field of photoelectric devices featuring low cost and high power conversion efficiency (PCE). However, the photovoltaic performance of DSSCs based on TiO2 ETL is still confined by the undesirable charge recombination occurring in TiO2 layer (intrinsic defects), dye layer (self-quenching) and at the interface between TiO2 and electrolyte (back electron transfer). Herein, we firstly adopted a trisiloxane molecule (denoted as TSi) to holistically reduce the abovementioned charge recombination of DSSCs via passivating surface defects of TiO2, fine-tuning dye molecules arrangement and forming interfacial energy barrier. As a result, the Z907-based DSSCs with TiO2/TSi ETL deliver a high PCE of 9.43%, increasing over 16% than that of DSSCs without TSi treatment. Meanwhile, the DSSCs based on TiO2/TSi ETL present stronger endurance to high humidity and better long-term stability versus that of the DSSCs without TSi treatment. Our work provides a simple yet effective strategy to holistically reduce charge recombination of devices for improving the photovoltaic performance and stability of DSSCs.