Efficient Charge Carrier Transfer Research Articles

Stabilizing the Electrochemistry of Lithium-Selenium Battery via In situ Gelated Polymer Electrolyte: A Look from Anode

Li metal possesses a high theoretical specific capacity, high electronic conductivity, and a low electrochemical potential, making it a promising anode material for building next-generation rechargeable metal batteries. In case conventional liquid electrolytes were used, and the anode using Li metal has been hindered by unstable(electro)chemistry at Li/electrolyte interface and the accompanied dendrite issue. Specifically, for the Li-Se batteries, the dissolution and shuttle of polyselenide intermediates lead to the deposition of poorly-conductive species on the anode, which further aggravates the chemical environment at the anode. In this work, we proposed to stabilize the Li-Se electrochemistry by constructing a gel polymer electrolyte via in situ gelations of conventional ether-based electrolytes at room temperature. The results demonstrate that the in situ gelated electrolyte helps to build electrochemically stable electrode/electrolyte interfaces and promote the efficient transfer of charge carriers across the interface. Compared with the liquid electrolytes, the gelated electrolyte shows improved chemical compatibility with the Li metal anode, which effectively alleviates the unfavorable side reactions and dendrite formation at the anode/electrolyte interface, and the polyselenide shuttle from the cathode to the anode. As a result, the Li-Se battery shows a higher Coulombic efficiency and improved cycling performance.

Highly efficient photocatalytic hydrogen evolution by using Rh as co-catalyst in the Cu/TiO2 system

Cu/TiO2 was modified by adding Rh as co-catalyst and used as a highly efficient photocatalyst for the hydrogen evolution reaction. A low amount of Rh was loaded onto Cu/TiO2 by the deposition-precipitation with urea (DPU) method to observe the effect on the hydrogen production displayed by different samples. The Rh–Cu/TiO2 oxide structure exhibited a remarkably high photocatalytic hydrogen evolution performance, which was about twofold higher than that of the Cu/TiO2 monometallic photocatalyst. This outstanding performance was due to the efficient charge carrier transfer as well as to the delayed electron-hole recombination rate caused by the addition of Rh. The influence of the different parameters of the photocatalyst synthesis and reaction conditions on the photocatalytic activity was investigated in detail. Hydrogen evolution was studied using methanol, ethanol, 2-propanol and butanol as scavengers with an alcohol:water ratio of 20:80. The methanol-water system, which showed the highest hydrogen production, was studied under 254, 365 and 450 nm irradiation; Rh–Cu/TiO2 showed high photocatalytic activity with H2 production rates of 9260, 5500, and 1940 μmol h−1 g−1, respectively. The Cu–Rh/TiO2 photocatalyst was active under visible light irritation due to its strong light absorption in the visible region, low band gap value and ability to reduce the electron (e−) and hole (h+) recombination.

Recent Progress on the Development of Carbon Nitride Based All‐Solid Z‐Scheme Photocatalyst for Solar Energy Conversion Applications

The visible‐light responsive semiconductor carbon nitride (C3N4) exhibits suitable electronic band structure, rich sources of precursors, and high stability, which is exploited to satisfy energy demands. However, the photocatalytic efficiency of C3N4 is limited because of its low surface area and low separation and transfer efficiency of charge carriers. As Z‐scheme strategy can effectively help C3N4 overcome its instinct shortage, this review will outline the recent significant progress on the development of C3N4‐based all‐solid Z‐scheme photocatalysts for energy‐conversion applications including water splitting and CO2 reduction. In the beginning, the fundamental principles of Z‐scheme will be introduced, especially for all‐solid‐state system. Then, the comprehensive account of the development of C3N4‐based Z‐scheme photocatalysts are discussed. Finally, perspectives on the challenges and future directions at the forefront of Z‐scheme photocatalysts are provided.

Recent development in graphdiyne and its derivative materials for novel biomedical applications.

Graphdiyne (GDY), which possess sp- and sp2-hybridized carbon and Dirac cones, offers unique physical and chemical properties, including an adjustable intrinsic bandgap, excellent charge carrier transfer efficiency, and superior conductivity compared to other carbon allotropes. These exceptional qualities of GDY and its derivatives have been successfully used in a variety of fields, including catalysis, energy, environmental protection, and biological applications. Herein, we focus on the potential application of GDY and its derivatives in the biomedical domain, including biosensing, biological protection, cancer therapy, and antibacterial agents, demonstrating how the biomimetic behavior of these materials can be a step forward in bridging the gap between nature and applications. Considering the excellent biocompatibility, solubility and selectivity of GDY and its derived materials, they have shown great potential as biosensing and bio-imaging materials. The unusual combination of properties in GDY has been used in biological applications such as "OFF-ON" DNA detection and enzymatic sensing, where GDY has a greater adsorption capacity than graphene and other 2D materials, resulting in increased sensitivity. GDY and its derivatives have also been used in cancer treatment due to their high doxorubicin (DOX) loading capacity (using-stacking) and photothermal conversion ability, and radiation protection since their initial biological use. The poor biodegradation rate of graphene demands the search for new nanomaterials. Accordingly, GDY has better biocompatibility and bio-safety than other 2D nanomaterials, especially graphene and its oxide, due to its absence of aggregation in the physiological environment. Thus, GDY-based nanomaterials have become promising candidates as bio-delivery carriers. Besides, GDY and GDY-based materials have also shown interesting applications in the fields of cell-culture, cell-growth and tissue engineering. Herein, we present a comprehensive review on the applications of GDY and its derivatives as biomedical materials, followed by their future perspectives. This review will provide an outlook for the application of graphene and its derivatives and may open up new horizons to inspire broader interests across various disciplines. Finally, the future prospects for GDY-based materials are examined for their potential biological use.

The synergistic effects of acid treatment and silver (Ag) loading for substantial improvement of photoelectrochemical and photocatalytic activity of Na2Ti3O7/TiO2 nanocomposite

This study investigated the effects of acid treatment and silver (Ag) loading on a Na2Ti3O7/TiO2 nanocomposite (NTO) synthesized through a hydrothermal method to improve its photoelectrochemical (PEC) performance and photodegradation of Rhodamine B (RhB). Due to the high specific surface area of this nanocomposite (199.06 m2/gr) and the high dispersal of the Ag nanoparticles on the surface of the catalyst, the best photocatalytic efficiency was obtained by using a very small percentage of optimized silver loading. The changes in the morphology, chemical state, and optical property of the NTO caused by the acid treatment and Ag loading were investigated by different analyses. Under visible light irradiation, 97.3% of the RhB in the aqueous solution was photodegraded by the optimized NTO with 0.1 M HCl treatment and 0.5 wt% Ag loading (NTOH0.1/Ag0.5), which is substantially higher than that photodegraded by the pristine NTO. The PEC properties of the NTOH0.1/Ag0.5 photoanode showed 2.7 times higher photocurrent density than that of untreated NTO. Combined analyses of Mott-Schottky plots and electrochemical impedance spectroscopy (EIS) of the NTOH0.1/Ag0.5 nanocomposite confirmed that the acid treatment and silver (Ag) loading increased both the donor concentration (ND) and the charge carrier transfer efficiency, resulting in substantially improved PEC performance.

In situ one-pot fabrication of MoO3−x clusters modified polymer carbon nitride for enhanced photocatalytic hydrogen evolution

Developing low-cost and high-efficient noble-metal-free cocatalysts has been a challenge to achieve economic hydrogen production. In this work, molybdenum oxides (MoO3−x) were in situ loaded on polymer carbon nitride (PCN) via a simple one-pot impregnation-calcination approach. Different from post-impregnation method, intimate coupling interface between high-dispersed ultra-small MoO3−x nanocrystal and PCN was successfully formed during the in situ growth process. The MoO3−x-PCN-X (X=1, 2, 3, 4) photocatalyst without noble platinum (Pt) finally exhibited enhanced photocatalytic hydrogen performance under visible light irradiation (λ>420 nm), with the highest hydrogen evolution rate of 15.6 µmol/h, which was more than 3 times that of bulk PCN. Detailed structure-performance revealed that such improvement in visible-light hydrogen production activity originated from the intimate interfacial interaction between high-dispersed ultra-small MoO3−x nanocrystal and polymer carbon nitride as well as efficient charge carriers transfer brought by Schottky junction formed.

A Cross‐Linked PCBM Interlayer for Efficient and UV‐Stable Methylammonium‐Free Perovskite Solar Cells

Interfacial engineering is crucial for perovskite solar cells (PSCs) to ensure efficient charge carrier transfer, and pivotal for device performances. Herein, a novel cross‐linked PCBM (CL‐PCBM) interlayer at the perovskite/electron transport layer (ETL) interface of the methylammonium‐free PSC device is incorporated. The dimeric PCBM interlayer prepared using a facile UV cross‐linking technique concurrently improves the quality of the resultant perovskite film and the charge transfer capability of the ETL, leading to significantly enhanced device photovoltaic performances. In addition, the PSC devices integrating the CL‐PCBM interlayers exhibit superior humidity and UV stabilities. The successful employment of the CL‐PCBM interlayer can bring new insight into the design and engineering of high‐quality interfaces for efficient PSCs.

Graphdiyne: A Rising Star of Electrocatalyst Support for Energy Conversion

AbstractGraphdiyne (GDY), a rising star of 2D carbon allotropes with one‐atom‐thick planar layers, has achieved the coexistence of sp‐ and sp2‐hybridized carbon atoms in a 2D planar structure. In contrast to the prevailing carbon allotropes, GDY possesses Dirac cone structures, which endow it with unique chemical and physical properties, including an adjustable inherent bandgap, high‐speed charge carrier transfer efficiency, and excellent conductivity. Additionally, GDY also displays great potential in photocatalysis, rechargeable batteries, solar cells, detectors, and especially electrocatalysis. In this work, various GDY‐supported electrocatalysts are described and the reasons why GDY can act as a novel support are analyzed from the perspective of molecular structure, electronic properties, mechanical properties, and stability. The various electrochemical applications of GDY‐supported electrocatalysts in energy conversion such as hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, overall water splitting, and nitrogen reduction reaction are reviewed. The challenges facing GDY and GDY‐based materials in future research are also outlined. This review aims at providing an in‐depth understanding of GDY and promoting the development and application of this novel carbon material.

A hybrid artificial photosynthesis system with molecular catalysts covalently linked onto TiO2 as electron relay for efficient photocatalytic hydrogen evolution

Efficient charge carrier transfer from light harvesters to catalysts greatly determines the photocatalytic activity in an artificial photosynthesis (AP) system for solar hydrogen evolution. In this study, an AP system composed of xanthene dye as light harvester and cobaloxime molecular complex as catalyst, with TiO2 as electron relay, was designed for photocatalytic hydrogen evolution under visible light (λ > 420 nm). It was demonstrated that with cobaloxime molecule covalently linked onto the TiO2 electron relay, the resulting hybrid AP system exhibited much increased photocatalytic activity as compared to that without TiO2. The greatly increased photocatalytic activity should be due to the efficient electron transfer from xanthene dye as light harvester and cobaloxime molecular complex as catalyst, shuttled by the TiO2 electron relay, for the following water reduction reaction. The present study demonstrates a facile and feasible strategy to guide the design of high performance AP systems through the electron relay shuttled and promoted charge transfer process.

Sol-Gel Processed TiO2 Nanotube Photoelectrodes for Dye-Sensitized Solar Cells with Enhanced Photovoltaic Performance.

The performance of dye-sensitized solar cells (DSCs) critically depends on the efficiency of electron transport within the TiO2-dye-electrolyte interface. To improve the efficiency of the electron transfer the conventional structure of the working electrode (WE) based on TiO2 nanoparticles (NPs) was replaced with TiO2 nanotubes (NTs). Sol-gel method was used to prepare undoped and Nb-doped TiO2 NPs and TiO2 NTs. The crystallinity and morphology of the WEs were characterized using XRD, SEM and TEM techniques. XPS and PL measurements revealed a higher concentration of oxygen-related defects at the surface of NPs-based electrodes compared to that based on NTs. Replacement of the conventional NPs-based TiO2 WE with alternative led to a 15% increase in power conversion efficiency (PCE) of the DSCs. The effect is attributed to the more efficient transfer of charge carriers in the NTs-based electrodes due to lower defect concentration. The suggestion was confirmed experimentally by electrical impedance spectroscopy measurements when we observed the higher recombination resistance at the TiO2 NTs-electrolyte interface compared to that at the TiO2 NPs-electrolyte interface. Moreover, Nb-doping of the TiO2 structures yields an additional 14% PCE increase. The application of Nb-doped TiO2 NTs as photo-electrode enables the fabrication of a DSC with an efficiency of 8.1%, which is 35% higher than that of a cell using a TiO2 NPs. Finally, NTs-based DSCs have demonstrated a 65% increase in the PCE value, when light intensity was decreased from 1000 to 10 W/m2 making such kind device be promising alternative indoor PV applications when the intensity of incident light is low.

High Performance Planar Structure Perovskite Solar Cells Using a Solvent Dripping Treatment on Hole Transporting Layer

Perovskite solar cell efficiency is not only related with material properties, but also affected by the interface engineering that used in perovskite solar cells. The perovskite film/electrode interface properties play important roles in charge carrier extraction, transport, and recombination. To achieve better interface contact for the device operation, proper interlayers or surface treatment should be applied. In this study, we applied a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) interlayer with a solvent/solution washing treatment as the hole transport layer. It showed that by the solvent/solution treatment, the PEDOT:PSS film conductivity was significantly enhanced, and hence, the charge carrier transfer efficiency was efficiently improved, and the device short-circuit current density was enlarged. Finally, the device efficiency significantly increased from 14.8% to 16.2%.

Synthesis of Bi₂MoO6/Bi₂Ti₂O7 Z-Scheme Heterojunction as Efficient Visible-Light Photocatalyst for the Glycolic Acid Degradation.

A novel Bi₂MoO6/Bi₂Ti₂O7 heterojunction photocatalyst was firstly prepared by a simple solvothermal route. The as-synthesized photocatalysts were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence spectra. The effect of the material ratio, solution pH, and the salinity on glycolic acid degradation were discussed. The Bi₂MoO6/Bi₂Ti₂O7 (2:1) nanocomposite exhibits highest photocatalytic performance and chemical stability. The glycolic acid degradation efficiency can reach 99.9% at pH 4 after 150 min irradiation under visible light. The enhanced photocatalytic activity can be ascribed to the heterojunction interface in the composite, which is beneficial to the efficient charge carriers transfer. The degradation conforms to the pseudo-first-order kinetics. According to the oxidation species trapping experiments, the ·O₂-, h+ and ·OH are found to play important roles in the photocatalytic degradation and ·O₂- is the main active species. The possible photocatalytic mechanism was further discussed on account of valence band, conduction band positions and possible transition states.

Performance of ZIF-67 – Derived fold polyhedrons for enhanced photocatalytic hydrogen evolution

Metal-organic framework (MOF) is one of the most promising precursors for the fabrication of advanced photo-semiconductors or cocatalysts due to its diverse structures and unique properties. However, the primitive MOF can not show greater potential and application value. Here Co-ZIF-67 dodecahedron was controllably carved via the different ways for efficiently boosting the photo-catalytic property of hydrogen evolution. This reasonable design can not only preserve polyhedron characteristics with the large specific surface area of ZIF-67, but also improve H2-evolution performance in Eosin Y sensitization system, which depends on the enhanced electronegativity of the surface of ZIF-6 derived polyhedrons and the quite strong adsorption of H and H2O by Co-site. Meanwhile, ligand group or hetero-atom adjacent to metal Co atom owing to the introduction of electronegative heteroatoms overturns the inherent structure and properties of ZIF-67 to a certain extent thereby rearranging the electron distribution and improving transfer efficiency of charge carriers. Additionally, the structural evolution of ZIF-67 constructs an efficient transport channels for migration of electron, which eliminates the resistance to be overcome when electrons migrate from the inside of a semiconductor to the surface. And the increase of optical absorption density caused by hyperchromicity effect is also a factor that can not be ignored for evolving the co-catalytic performance of ZIF-67.

Bismuth impregnated biochar for efficient estrone degradation: The synergistic effect between biochar and Bi/Bi2O3 for a high photocatalytic performance

An innovative advanced oxidation process was successfully developed to photocatalytic-degradation of estrone through the synergistic effect of biochar and Bi/Bi2O3 in bismuth-containing photocatalytic biochar (BiPB). The highest reaction rate constant (kobs) of estrone degradation by BiPB was 0.045 min−1 under the conditions of initial concentration of estrone =10.4 μmol L−1, [BiPB] =1 g L−1, pH = 7.0. The kobs was almost tenfold and more than 20 times than that of biochar without bismuth impregnation and pristine Bi/Bi2O3, respectively. The best photocatalytic performance of BiPB composites for the degradation of estrone was primarily attributed to generation of OH radicals. Impregnation of bismuth helped control the concentration of persistent free radicals (PFRs) and develop a hierarchical porous structure of biochar. The presence of biochar facilitated pre-concentration estrone on BiPB and improved the separation and transfer efficiency of charge carriers. The synergistic effect between biochar and Bi/Bi2O3 contributed to the generation of OH radicals for estrone degradation under neutral pH conditions. The transformation pathway of estrone was also proposed based on the measured transformation products in the presence of BiPB. The high efficiency of BiPB composites indicated that this easily-obtained material was promising for estrone-wastewater treatment applications as a low-cost composite photocatalyst.

Heavy Mediator at Quantum Dot/Graphene Heterojunction for Efficient Charge Carrier Transfer: Alternative Approach for High-Performance Optoelectronic Devices.

Two-dimensional (2D) material nanocomposites have emerged as a material system for discovering new physical phenomena and developing novel devices. However, because of the low density of states of most two-dimensional materials such as graphene, the heterostructure of nanocomposites suffers from an enhanced depletion region, which can greatly reduce the efficiency of the charge carrier transfer and deteriorate the device performance. To circumvent this difficulty, here we propose an alternative approach by inserting a second 2D mediator with a heavy effective mass having a large density of states in-between the heterojunction of 2D nanocomposites. The mediator can effectively reduce the depletion region and form a type-II band alignment, which can speed up the dissociation of electron-hole pairs and enhance charge carrier transfer. To illustrate the principle, we demonstrate a novel stretchable photodetector based on the combination of graphene/ReS2/perovskite quantum dots. Two-dimensional ReS2 acts as a mediator in-between highly absorbing perovskite quantum dots and a high-mobility graphene channel and a thiol-based linker between the ReS2 and the perovskite. It is found that the optical sensitivity can be enhanced by 22 times. This enhancement was ascribed to the improvement of the charge transfer efficiency as evidenced by optical spectroscopy measurements. The produced photosensors are capable of reaching the highest reported value of photoresponsivity (>107 A W-1) and detectivity compared to previously studied stretchable devices. Mechanical robustness with tolerable strain up to 100% and excellent stability make our device ideal for future wearable electronics.

Ligand Engineering for Improved All‐Inorganic Perovskite Quantum Dot‐MoS2 Monolayer Mixed Dimensional van der Waals Phototransistor

AbstractCombining intriguing physical properties of 2D crystals and intrinsically remarkable optical properties of halide perovskite quantum dots (QDs), the 0D–2D perovskite QD–based mixed dimensional van der Waals heterostructure (MvdWH) is considered as promising for optoelectronic applications. Even though the interfacial electronic structure of MvdWHs is sufficiently engineered to manipulate the charge carrier behavior, the issue of interfacial charge transfer efficiency originating from the residue ligands that are inevitably introduced by the QDs is still prominently remained. From this perspective, for the first time, a solution‐processed surface ligand density control strategy is demonstrated to balance the QD surface passivation and the interfacial charge carrier extraction and injection efficiency in the 0D–2D MvdWH system. The accurate adjustment of ligand density outside QDs enables the subsequent modulation on interfacial charge carrier transfer efficiency from the aspect of electronic and optoelectronic properties. Furthermore, such kind of ligand engineering toward MvdWH interface is substantially demonstrated in a photogating mechanism–based phototransistor with an improved photoresponsivity as high as 1.13 × 105 A W−1. These results may push forward the evolution of 0D–2D mixed dimensional van der Waals optoelectronics.

Carbon‐Coated Cu nanoparticles as a Cocatalyst of g‐C3N4 for Enhanced Photocatalytic H2 Evolution Activity under Visible‐Light Irradiation

The photocatalytic H2 evolution is an important technology to solve the energy crisis. The hydrogen evolution rate of the graphite carbon nitride (g‐C3N4) system in triethanolamine solution as sacrificial agent is clearly higher than that in methanol solution. But up to now, most of the Cu nanoparticles as cocatalyst of g‐C3N4 photocatalytic systems for hydrogen evolution are performed in methanol solution because Cu nanoparticles are unstable in triethanolamine solution. Here, carbon‐coated Cu nanoparticles as a cocatalyst of g‐C3N4 composites (Cu@C/g‐C3N4) are prepared by a simple two‐step technology that includes annealing followed by grinding. The compositions, morphology, and optical and photoelectrochemical properties of the composites are characterized by means of physicochemical techniques. The prepared composition is used to generate hydrogen under visible‐light irradiation in triethanolamine solution. The results show that the hydrogen evolution rate of the optimal Cu@C/g‐C3N4 is up to 265.1 μmol g−1 h−1, which is close to the activity of 0.5% Pt/g‐C3N4, and after four repeated reactions, the photocatalytic activity decreases only by ≈15%. The good photocatalytic activity and stability result from Cu nanoparticles increase the transfer efficiency of charge carriers by trapping the photogenerated electrons produced by g‐C3N4 and the protective effect of carbon layer on Cu nanoparticles.

Solid salt confinement effect: An effective strategy to fabricate high crystalline polymer carbon nitride for enhanced photocatalytic hydrogen evolution

Polymer carbon nitrides (PCN) are one of promising photocatalysts in water splitting, but their low crystallinity usually leads to slow transfer efficiency of charge carriers. Herein, we presented a solid-salt-assisted growth strategy to fabricate highly crystalline polymer carbon nitride (CPCN). The high-melting-point KCl salt was used as an easily removable solid template, where the confined space guides efficient growth of CPCN. The fabricated CPCN samples show high crystalline quality with clear long-range periodicity and large grain sizes up to 400 nm. The combination of structural characterization analyses and first-principles energetic calculations reveals that CPCN is composed of chain-like melon motifs with intercalated K+ ions. The photocatalytic activity of CPCN in hydrogen evolution reaction is over 22 times higher than that of pristine PCN, the apparent quantum efficiency at λ = 420 ± 5 nm is up to 11.4%. This work provides a simple and general protocol for crystallinity and performance enhancement in a wide range of polymeric photocatalyst materials.

Rational design of graphic carbon nitride copolymers by molecular doping for visible-light-driven degradation of aqueous sulfamethazine and hydrogen evolution

Carbon nitride is a promising metal-free visible light driven photocatalyst and sustainable material for address contaminant pollution and water splitting. However, the insufficient visible light absorption and fast charge recombination of carbon nitride have limited its practical application. Herein, the self-assembly carbon nitride (denoted as TCN) by molecular doping copolymerization of urea and 2-thiobarbitucid acid (TA) was prepared. XPS and elemental analytical results indicated that TA was doped in the framework of carbon nitride successfully. The self-assembly copolymerization would result in the change of morphology, intrinsic electron and band structure of carbon nitride. Theoretical calculations and experiments confirm that the band gap of TCN could be adjusted by changing the amount of 2-thiobarbitucid acid. Moreover, the efficiency of charge carrier transfer and separation was greatly enhanced. As a result, the optimized photocatalyst TCN-0.03 exhibited superior activity with a high reaction rate of 0.058 min−1 for the degradation of sulfamethazine under visible light irradiation, which is 4.2 times higher than that of urea based carbon nitride (U-CN). As a multifunctional photocatalyst, TCN-0.03 showed enhanced activity for hydrogen production (55 μmol h−1), which was 11 times higher than U-CN. The apparent quantum efficiency reached to 4.8% at 420 nm. A possible mechanism was proposed to explain the photocatalytic reaction process. This work provides insight into the rational design of modified carbon nitride by other organic monomers copolymerization to enhance the photocatalytic activity.

Study and Development of Photovoltaic Structures Based on Quantum Dot Solids of PbS with Various Ligands

The photoconductivity of condensates of lead-sulfide quantum dots (QDs)—QD solids—with various organic ligands is studied. It is demonstrated that the QD solid photoconductivity increases exponentially with a reduction in length of ligand molecules and does not depend on their chemical structures, since it is governed by hopping transport of charge carriers. In contrast, the photocurrent in photovoltaic ITO/PEDOT: PSS/PbS/ZnO/Al elements depends on the ligand structure, since this structure sets the positions of QD energy levels and thus affects the efficiency of charge carrier transfer to electrodes. The difference between mechanisms of generation of photoconductivity and photovoltaic currents is discussed.