ZnO Electron Transport Layer Research Articles

Comparative study on perovskite solar cells using P_ZnO, Al_ZnO and In_ZnO as ETMs by SCAPS-1D

This study uses the SCAPS 1D software to analyze solar cells with lead iodide perovskite (CH3NH3PbI3) as the active material and three different types of ZnO doping: undoped (P_ZnO), aluminum-doped (Al_ZnO), and indium-doped (In_ZnO) as the electron transport layer (ETL). This study aims to investigate the effects of charge carrier density on the J-V characteristics and electrical properties (Jsc, Voc, FF, Eff) of a solar cell structure made up of FTO/ETL/CH3NH3PbI3/CuInSe2/Au. Gold makes up the back contact, and tin oxide doped with fluorine (FTO) makes up the front contact. These two compounds have work roles are 5.47 eV and 4.4 eV respectively. Zinc oxide, both undoped and doped, makes up the electron transport layer, whereas methyl ammonium lead iodide makes up the absorber layer. Thin sheets, indium diselenide, and copper make up the hole transport layer. An optimal perovskite layer was obtained by decreasing the electron transportation layer's thickness (ETL) from 500 to 100 nm. For the In_ZnO ETL, this optimization was accomplished at 300K working temperature. Reduced ETL thickness was shown to result in higher efficiency (above 27%), as well as higher fill factor (above 87%). With a Voc value of 1.180V, a FF value of 87.55%, and a Jsc value of 26.276mA/cm2, the greatest efficiency performance of 27.15% was found. Using an absorber layer made of CH3NH3PbI3 with a thickness of 800 nm and indium-doped oxide of zinc (In_ZnO) is the layer that transports electrons, this performance was achieved. The results are obtained at a constant irradiance level of 1000 W/m2, under the AM1.5G spectrum.

Unraveling the electrical energy loss in silver nanowire electrodes for flexible and Large-Area organic solar cells

Although the transparency and sheet resistance of silver nanowire (AgNW) electrodes are comparable to those of rigid indium-tin-oxide electrodes, flexible organic solar cells (FOSCs) are still less efficient than their rigid counterparts. Herein, by recording the microscopic photocurrent images of AgNW-based FOSCs in operation, it has been revealed that the limited lateral charge collection range of AgNW leads to inevitable electrical energy loss. The regulation of carrier mobility and energy level of adjacent ZnO electron transport layer increases the effective collection range of AgNWs by 1.8 times and uniform the electrical potential distribution in FOSCs. The D18:Y6:PC71BM-based FOSCs achieve a power conversion efficiency of approaching 18%. Moreover, the performance drop of large-area FOSCs is significantly reduced due to the improved charge collection on large area scale. This work provides an intuitive insight into the electrical energy loss mechanism of AgNW electrodes and demonstrates an electric field regulation strategy in FOSCs.

Numerical study of charge transport layers in inverted ternary organic photovoltaic cells

This study investigates the crucial role of charge transport layers in enhancing the performance of inverted organic photovoltaic cells (OPVs) through advanced numerical simulations using OghmaNano software. OPVs offer distinct advantages, including lightweight, flexibility, and potential cost-effectiveness compared to traditional silicon-based counterparts, making them pivotal for sustainable energy solutions. We evaluate the efficiency of inverted (iOPVs) employing binary (PM6:L8-BO) and ternary (PM6:D18:L8-BO) active layers, utilizing electron transport layers (ETLs) including ZnO, TiO2, and SnO2, and hole transport layers (HTLs) such as MoO3, PEDOT, and WO3. Results highlight ZnO with a 15 nm-thick layer combined with MoO3 HTL achieving an impressive efficiency of 18.89% in ternary devices, demonstrating the effectiveness of organic materials and ternary blends. The study demonstrates that TiO2 or SnO2 ETLs can compete effectively with ZnO ETLs, particularly when used at thinner thicknesses, and offers alternative fabrication methods. It suggests that employing thin ETL layers (15 ± 2 nm) could significantly enhance the performance of iOPV devices. Simulations are crucial for optimizing iOPV device configurations with thin ETL layers, enabling rapid prototyping and cost-effective exploration of material combinations and device architectures. These layers play a critical role in balancing charge carrier generation and transport efficiency, collectively maximizing device performance. Overall, the study underscores the pivotal role of simulations and optimized layer thicknesses in advancing OPV technology by refining manufacturing processes and accelerating the adoption of OPVs for sustainable energy solutions.

Application of a NADH-modified ZnO electron transport layer in high performance organic solar cells

A novel ZnO:NADH composite electron transport layer is constructed, and the efficiency of organic solar cells (OSCs) with PM6:L8-BO as the active layer has improved from 17.43% to 18.21%.

One-Step Preparation of ZnO Electron Transport Layers Functionalized with Benzoic Acid Derivatives

One-Step Preparation of ZnO Electron Transport Layers Functionalized with Benzoic Acid Derivatives

High-performance semi-transparent organic solar cells driven by the dipole-controlled optoelectrical response of bilateral self-assembled monolayer strategy

A bilateral self-assembled monolayer (SAM) strategy is proposed to improve the performance of both opaque/translucent and rigid/flexible organic solar cells (OSCs), which have great potential for various high-value applications such as portable, building-integrated and vehicle-integrated photovoltaics. By applying the dipole-controlled SAMs to both ITO/ZnO and ZnO/active layer interfaces, the work function of the ZnO electron transport layer was reduced, which improved charge transport and reduced carrier recombination at the interface. The opaque OSCs with the bilateral SAM demonstrated significant performance improvement with power conversion efficiencies (PCEs) reaching 17.20% and 16.96% for rigid and flexible OSCs. When used in semi-transparent OSCs together with MoO3/Ag/MoO3 electrode, in semi-transparent (ST) OSCs, PCE and average visible transmittance (AVT) can be improved simultaneously, and 10.37% PCE and 36.27% AVT demonstrate a remarkable light utilization efficiency (LUE) of 3.85%. Finally, the large area (10 × 10 cm2) ST-OSC module was fabricated and demonstrated a PCE of 8.17% and LUE of 2.5%, among the best-reported values for inverted module devices. The developed bilateral SAM strategy can be useful in developing high-performance OSCs of both opaque/translucent and rigid/flexible types for various practical applications.

A simple strategy passivating ZnO electron transport layers for realizing high efficiency in organic solar cells

Sol–gel processed ZnO films are widely used as electron transport layers (ETLs) in organic solar cells (OSCs). However, defects caused by COOH, OH, and vacancies of oxygen in ZnO ETLs are harmful for electron extraction and transport processes in OSCs. Here, a simple and effective strategy is reported to passivate free OH via hydrogen bond of HO…NH2. A small molecule of biuret is introduced into ZnO precursor as an additive to form ZnO films. The hydrogen bond of HO…NH2 is confirmed by XPS and FT-IR in this study, which passivates traps originated from free OH. The passivated ZnO ETLs exhibit better morphology and higher electron mobility than pristine ZnO ETLs. In OSCs with fullerene and non-fullerene light absorbers, the cells with biuret-doped ZnO ETLs obtain improved power conversion efficiency (PCE), which prove the generality of biuret doped ZnO ETLs. Eventually, a maximal PCE of 18.19 % is obtained when PM6:L8-BO is selected as light absorber. Furthermore, the contributions of biuret are discussed in this work.

Passivating defects in ZnO electron transport layer for enhancing performance of red InP-based quantum dot light-emitting diodes

ZnO nanoparticles (NPs) are considered the most promising materials for electron transport layer (ETL) in quantum dot light-emitting diodes (QLEDs). Herein, we employed a synergistic strategy of Mg doping and ZnMgO shell coating to modify the defect states and energy levels of ZnO NPs. Mg doping mitigated the exciton luminescence quenching caused by charge transfer. A ZnMgO shell was also applied to coat the Mg-doped ZnO (ZMO) NPs to passivate surface oxygen defects further. Consequently, QLEDs utilizing ZMO@ZnMgO ETL demonstrate external quantum efficiency and maximum current efficiency of 9.0 % and 11.5 cd A−1. This work shows an effective defect passivation strategy to enhance the performance of red-emitting InP-based QLEDs.

Doping engineering of ZnO electron transporting layer for high performance CsPbI2Br inorganic perovskite solar cells

An inorganic CsPbI2Br perovskite has garnered significant interest due to its outstanding photoelectrical properties in recent years. However, CsPbI2Br-based perovskite solar cells (PSCs) generally suffer from large energy loss, hindering their further development. Herein, we proposed a facile and effective approach to dope the ZnO electron transporting layer (ETL) with alkaline earth metal ions to boost the photovoltaic performance of CsPbI2Br PSCs. Particularly, the ZnO ETL doped with Ca2+ can simultaneously ameliorate electron transport, energy level alignment, and the quality of the upper CsPbI2Br film, thus resulting in faster charge extraction and suppressed charge recombination. Consequently, the ZnO:Ca-based PSC achieves a champion power conversion efficiency (PCE) of 16.39% with an excellent VOC of 1.292 V, while the control ZnO-based PSC just exhibits an inferior PCE of 14.22% with a VOC of 1.178 V. Furthermore, the ZnO:Ca-based devices also present considerable enhancements in device stability without encapsulation. Our work offers a promising strategy to mitigate the energy loss toward efficient and stable PSCs.

Spray deposited carbon nanotube embedded ZnO as an electrons transport layer in inverted organic solar cells

In this report, the synthesis and characterization of ZnO and carbon nanotube (CNT) embedded ZnO composite thin films are presented. The obtained ZnO and CNT composite ZnO thin films are used as an electron transport layer (ETL) for bulk heterojunction (BHJ) inverted organic solar cell (IOSC) with the architecture of ITO/ZnO:CNT/PTB7:PC71BM/MoO3/Ag. Both ZnO and CNT composite ZnO thin films exhibited a highly preferred c-axis oriented (002) diffraction peak and the peak position is shifted toward a lower angle after embedding CNT into the ZnO matrix. The transmittance slightly decreases after CNT is embedded into the ZnO matrix. Completely wrapped CNT with the ZnO was confirmed by Scanning electron microscope (SEM) measurement. The resistivity of ZnO decreased from 2.02 × 10−2 to 5.61 × 10−3 Ω-cm and mobility increased from 4.30 to 15.24 cm2/V-s after adding CNT into the ZnO matrix. CNT composite ZnO thin film surface is found to be hydrophobic, providing good interfacial contact with the BHJ layer resulting to improve fill factor (FF) of IOSC. The performance of IOSC with CNT composite ZnO ETL layer was significantly improved with a power conversion efficiency of 6.76%, open circuit voltage (VOC) of 700 mV, short circuit current density (JSC) of 20.05 mA/cm2 and FF of 48.17%, respectively.

Enhanced UV Absorption By 2D MoS2 Nanoparticles

MoS2 is one of the promising 2D materials that caught the interest of many research fields[1], [2] due to their size-dependent tunable bandgap and attractive magnetic, optical, and electrical properties[3]. Furthermore, recently there has been a growing interest in utilizing MoS2 for solar cell applications that demonstrated measurable device enhancements[4]–[6]. Hence, there is a great interest in understanding its potential for solar energy harvesting. In this study, we show a simple method to deposit a 2D layer of MoS2 nanoparticles (NPs) on top of Aluminum-doped Zinc oxide (AZO) layer (transparent conductive oxide) and investigate its spectral response and potential for application in optoelectronic systems.A thin film of 80 nm AZO layer was grown on a 4-inch quartz wafer using thermal Atomic Layer Deposition (ALD) with a 1:19 ratio which has shown good electrical and optical qualities for solar cell applications[7]. We deposited the MoS2 by spin-coating it on the AZO/quartz wafers for 40 sec at 1000 rpm. Incremental coating is carried on by dispersing seven layers with 500 μL of MoS2 in each step using a precise pipet to a cumulative dispersion volume of 3500 μL. The prepared samples were characterized using a UV-Vis-NIR spectrometer (Perkin Elmer Lambda) across a wide range of wavelengths (250-1200 nm) by measuring both transmittance and reflectance and calculating absorbance. Furthermore, the base AZO/quartz and quartz background signal were measured before spin-coating as reference.The obtained data shows a high absorbance effect due to MoS2 NPs at low wavelengths (<400 nm), where it peaks around 340 nm with an approximate absorbance of ~6.7%. Upon further examination, we notice that this behavior is not linear across the whole spectrum and instead is a function of (i) wavelength and (ii) MoS2 quantity which could be partially due to the quantum confinement effect of several layers of stacked 3D MoS2 nanoparticles[8]. This phenomenon could open the possibility of utilizing this material for low-wavelength filters or UV sensing applications[9]. Also, it can potentially be utilized for quantum down-conversion[10] of high-energy photons to re-emit photons at lower energies in order to enhance solar cells’ efficiencies and reduce thermal burden; however, further investigation is needed.[1] P. Zhou, C. Chen, X. Wang, B. Hu, and H. San, “2-Dimentional photoconductive MoS2 nanosheets using in surface acoustic wave resonators for ultraviolet light sensing,” Sensors and Actuators A: Physical, vol. 271, pp. 389–397, Mar. 2018, doi: 10.1016/j.sna.2017.12.007.[2] H. Dong et al., “Fluorescent MoS 2 Quantum Dots: Ultrasonic Preparation, Up-Conversion and Down-Conversion Bioimaging, and Photodynamic Therapy,” ACS Appl. Mater. Interfaces, vol. 8, no. 5, pp. 3107–3114, Feb. 2016, doi: 10.1021/acsami.5b10459.[3] K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, “Atomically Thin MoS 2 : A New Direct-Gap Semiconductor,” Phys. Rev. Lett., vol. 105, no. 13, p. 136805, Sep. 2010, doi: 10.1103/PhysRevLett.105.136805.[4] Y. Tsuboi et al., “Enhanced photovoltaic performances of graphene/Si solar cells by insertion of a MoS 2 thin film,” Nanoscale, vol. 7, no. 34, pp. 14476–14482, 2015, doi: 10.1039/C5NR03046C.[5] N. A. Abd Malek et al., “Ultra-thin MoS2 nanosheet for electron transport layer of perovskite solar cells,” Optical Materials, vol. 104, p. 109933, Jun. 2020, doi: 10.1016/j.optmat.2020.109933.[6] Y.-J. Huang, H.-C. Chen, H.-K. Lin, and K.-H. Wei, “Doping ZnO Electron Transport Layers with MoS 2 Nanosheets Enhances the Efficiency of Polymer Solar Cells,” ACS Appl. Mater. Interfaces, vol. 10, no. 23, pp. 20196–20204, Jun. 2018, doi: 10.1021/acsami.8b06413.[7] S. Abdul Hadi, G. Dushaq, and A. Nayfeh, “Effect of atomic layer deposited Al 2 O 3 :ZnO alloys on thin-film silicon photovoltaic devices,” Journal of Applied Physics, vol. 122, no. 24, p. 245103, Dec. 2017, doi: 10.1063/1.4990871.[8] T. Li and G. Galli, “Electronic Properties of MoS 2 Nanoparticles,” J. Phys. Chem. C, vol. 111, no. 44, pp. 16192–16196, Nov. 2007, doi: 10.1021/jp075424v.[9] Z. Lou et al., “High-performance MoS_2/Si heterojunction broadband photodetectors from deep ultraviolet to near infrared,” Opt. Lett., vol. 42, no. 17, p. 3335, Sep. 2017, doi: 10.1364/OL.42.003335.[10] A. P. Sunitha, P. Praveen, M. K. Jayaraj, and K. J. Saji, “Upconversion and downconversion photoluminescence and optical limiting in colloidal MoS2 nanostructures prepared by ultrasonication,” Optical Materials, vol. 85, pp. 61–70, Nov. 2018, doi: 10.1016/j.optmat.2018.08.038.[11] Y. Wu et al., “Monolithic integration of MoS 2 -based visible detectors and GaN-based UV detectors,” Photon. Res., vol. 7, no. 10, p. 1127, Oct. 2019, doi: 10.1364/PRJ.7.001127. Figure 1

Modeling and simulation of > 19% highly efficient PbS colloidal quantum dot solar cell: A step towards unleashing the prospect of quantum dot absorber

We used the SCAPS-1D simulation tool to maximize the performance of lead sulfide (PbS) solar cells. A PbS solar cell was first modeled and then experimentally verified from past research. The ZnO electron-transport layer (ETL) was then replaced with ZnO:Al ETL material. Additionally, the fluorine-doped tin oxide work function, PbS-TBAI, ZnO:Al layer thicknesses, ZnO:Al/PbS-TBAI, PbS-TBAI/PbS-EDT defect density, PbS-TBAI defect density, ZnO:Al, and PbS-TBAI doping concentration were optimized. Results showed a greater alignment of the absorber-layer valence band with the HOMO and LUMO of ZnO:Al than that of ZnO ETL. The PbS solar cell exhibited the greatest efficiency at the optimum values of 0.4 µm, 0.04 µm, 1019 cm–3, 4.0 eV, 1017 cm–3, 1014 cm–2, 1018 cm–2, and 3.8 eV for absorber thickness, ETL thickness, ETL doping concentration, work function of front contact, PbS-TBAI doping concentration, and electron affinity of ZnO:Al, respectively. The PbS solar cell also performed best at interface defect densities of 1014 and 1018 cm–2 for ZnO:Al/PbS-TBAI and PbS-TBAI/PbS-EDT, respectively. The PCE of ZnO:Al ETL-based device also increased from 15.036% before optimization to 19.169% after. The optimized result was found to be affected by temperature. The PbS-optimized device with inorganic hole-transport layers (HTLs) demonstrated higher performance than the device with organic HTL. This finding was attributed to the low hole mobility in the organic HTL than those of inorganic ones. Therefore, the ZnO:Al ETL-based device was more efficient than the ordinary ZnO ETL-based device.

Vitamin C for Photo-Stable Non-fullerene-acceptor-Based Organic Solar Cells.

The recent advent of the new class of organic molecules, the so-called non-fullerene acceptors, has resulted in skyrocketing power conversion efficiencies of organic solar cells. However, rapid degradation occurs under illumination, particularly when photocatalytic metal oxide electron transport layers are used in these devices. We introduced vitamin C (ascorbic acid) into the organic solar cells as a photostabilizer and systematically studied its photostabilizing effect on inverted PBDB-T:IT-4F devices. The presence of vitamin C as an antioxidant layer between the ZnO electron transport layer and the photoactive layer strongly suppressed the photocatalytic effect of ZnO that induces NFA photodegradation. Upon 96 h of exposure to AM 1.5G 1 Sun irradiation, the reference devices lost 64% of their initial efficiency, while those containing vitamin C lost only 38%. The UV-visible absorption, impedance spectroscopy, and light-dependent voltage and current measurements reveal that vitamin C reduces the photobleaching of NFA molecules and suppresses the charge recombination. This simple approach using a low-cost, naturally occurring antioxidant, provides an efficient strategy for improving photostability of organic semiconductor-based devices.

Single, Double and ETL-Sandwiched PVPy Interlayer Effect on Charge Injection Balance and Performance of Inverted Quantum Dot Light-Emitting Diodes.

A desire to achieve optimal electron transport from the electron transport layer (ETL) towards the emissive layer (EML) is an important research factor for the realization of high performance quantum dot light-emitting diodes (QD-LEDs). In this paper, we study the effect of a single, double, and electron transport layer sandwiched Poly(4-vinylpyridine) (PVPy here on) on the charge injection balance and on the overall device performance of InP-based red quantum dot light emitting diodes (red QD-LEDs). The results showed general improvement of device characteristic performance metrics such as operational life with incorporation of a PVPy interlayer. The best performance was observed at a lower concentration of PVPy (@ 0.1 mg/mL) in interlayer with continual worsening in performance as PVPy concentration in the interlayer increased in other fabricated devices. The AFM images obtained for the different materials reported improved surface morphology and overall improved surface properties, but decreased overall device performance as PVPy concentration in interlayer was increased. Furthermore, we fabricated two special devices: in the first special device, a single 0.1 mg/mL PVPy sandwiched between two ZnO ETL layers, and in the second special device, two 0.1 mg/mL PVPy interlayers were inter-sandwiched between two ZnO ETL layers. Particular emphasis was placed on monitoring the maximum obtained EQE and the maximum obtained luminance of all the devices. The first special device showed better all-round improved performance than the second special device compared to the reference device (without PVPy) and the device with a single 0.1 mg/mL PVPy interlayer stacked between ZnO ETL and the emissive layer.

Tin-doped ZnO electron transport layer to improve performance of P3HT-based organic solar cells

Tin-doped ZnO electron transport layer to improve performance of P3HT-based organic solar cells

Examining the potential of non-toxic stable double perovskite solar cells based on Cs2CuSbX6

The main issues impeding the commercialization of perovskite solar cells are their toxicity and long-term stability. Thus, it is essential to find a robust and reliable alternative light absorber that is environmentally friendly and provides stability. Herein, we present stable and lead-free Cs2CuSbX6 (where X = Cl, Br, and I) double perovskite light harvesters as a substitute, which can render excellent efficiency and long-term stability. The double perovskite solar cells based on the Cs2CuSbX6 light harvester, the aluminium-doped ZnO electron transport layer, and the MoO3 and Cu2O hole transport layers are critically evaluated using the SCAPS-1D software package. The densities of defects and dopants as well as the thickness of the succeeding layers of the double perovskite solar cells are altered to extract high efficiency. With aluminium-doped ZnO serving as the electron transport layer, the optimized Cs2CuSbI6-based double perovskite solar cells attain a power conversion efficiency (PCE) of about ∼29% for both MoO3 and Cu2O hole transport layers. Several potential back electrodes are also investigated, and their impact on performance is assessed. The fluctuation in PCE concerning operating temperature is computed for authentic analysis of the double perovskite solar cells during real-time operation. Overall, in order to achieve high PCEs in Cs2CuSbI6-based double perovskite solar cells, it is crucial to consider both the thickness of the light harvester layer and the bulk defect density.

Suppressing Degradation in QLEDs via Doping ZnO Electron Transport Layer by Halides

AbstractRecent findings show that electron transport layers (ETLs) significantly influence the electroluminescence (EL) lifetime of quantum‐dot light‐emitting diodes (QLEDs). In this work, it is found that using halide dopants in the ZnO ETL significantly enhances device EL lifetime. Electrical, photoluminescence, and photoelectron spectroscopy measurements on QLEDs and specially designed devices are used for elucidating the root causes of the lifetime enhancement. Results show that charge transfer occurs at the ZnO/QDs interface in QLEDs, producing positively charged states in ZnO, subsequently leading to luminance loss, a mechanism that contributes to EL loss. Furthermore, XPS studies show that electrical stress of QLEDs leads to an increase in the concentration of ZnO species with higher oxidative states and that a correlation between the magnitude of EL loss and the concentration of these species exists. The use of halide dopants is found to reduce this interfacial charge transfer and the formation of the ZnO species with higher oxidative states, possibly due to the dopants role in acting as hole scavengers that trap and efficiently neutralize holes in ZnO. The findings underscore the significant role that managing positive charges in ZnO plays in EL lifetime and provide an effective strategy for achieving highly stable QLED.

Deep Insights into the Coupled Optoelectronic and Photovoltaic Analysis of Lead-Free CsSnI3 Perovskite-Based Solar Cell Using DFT Calculations and SCAPS-1D Simulations.

CsSnI3 is considered to be a viable alternative to lead (Pb)-based perovskite solar cells (PSCs) due to its suitable optoelectronic properties. The photovoltaic (PV) potential of CsSnI3 has not yet been fully explored due to its inherent difficulties in realizing defect-free device construction owing to the nonoptimized alignment of the electron transport layer (ETL), hole transport layer (HTL), efficient device architecture, and stability issues. In this work, initially, the structural, optical, and electronic properties of the CsSnI3 perovskite absorber layer were evaluated using the CASTEP program within the framework of the density functional theory (DFT) approach. The band structure analysis revealed that CsSnI3 is a direct band gap semiconductor with a band gap of 0.95 eV, whose band edges are dominated by Sn 5s/5p electrons After performing the DFT analysis, we investigated the PV performance of a variety of CsSnI3-based solar cell configurations utilizing a one-dimensional solar cell capacitance simulator (SCAPS-1D) with different competent ETLs such as IGZO, WS2, CeO2, TiO2, ZnO, PCBM, and C60. Simulation results revealed that the device architecture comprising ITO/ETL/CsSnI3/CuI/Au exhibited better photoconversion efficiency among more than 70 different configurations. The effect of the variation in the absorber, ETL, and HTL thickness on PV performance was analyzed for the above-mentioned configuration thoroughly. Additionally, the impact of series and shunt resistance, operating temperature, capacitance, Mott-Schottky, generation, and recombination rate on the six superior configurations were evaluated. The J-V characteristics and the quantum efficiency plots for these devices are systematically investigated for in-depth analysis. Consequently, this extensive simulation with validation results established the true potential of CsSnI3 absorber with suitable ETLs including ZnO, IGZO, WS2, PCBM, CeO2, and C60 ETLs and CuI as HTL, paving a constructive research path for the photovoltaic industry to fabricate cost-effective, high-efficiency, and nontoxic CsSnI3 PSCs.

Effect of solution-processed Mg-doped ZnO electron transport layer on the photodetector properties of MAPbI3 thin film

Effect of solution-processed Mg-doped ZnO electron transport layer on the photodetector properties of MAPbI3 thin film

Blue cadmium-free and air-fabricated quantum dot light-emitting diodes

Quantum dot (QD) materials have found increasing use in display applications because of their high color purity and fluorescence quantum yield, enabling devices with higher brightness and efficiency. However, to access large-area printing and coating methods that are carried out in ambient conditions, it is necessary to, first, move away from toxic cadmium, and second, to target materials that can be air-processed. Herein, we synthesize zinc selenide-based blue QD material and air-fabricate light-emitting diodes (LEDs) and single-carrier devices. The encapsulated devices were also measured under ambient conditions. Multi-shell-structured ZnSeTe/ZnSe/ZnS (core/shell/shell) QDs show pure deep blue/purple fluorescence emission with a high photoluminescence quantum yield of 78%. The blue QD-LED devices are fabricated in a conventional structure with bottom light emission with two electron transport materials (ZnO and ZnMgO). The QD-LED devices with ZnO electron transport layer show a maximum luminance of ∼6200 cd m−2 at 9 V with a turn-on voltage of 3.5 V and current efficacy of 0.38 cd A−1, while with ZnMgO electron transport layer, the devices show a maximum luminance of 3000 cd m−2 at 7 V with a turn-on voltage of 3 V and current efficacy of 0.6 cd A−1. Electron-only and hole-only devices were fabricated to show and confirm the underlying charge transport mechanisms. To our knowledge, these results show for the first-time air-fabricated ZnSe-based QD-LEDs, paving the way for scaling up display applications and moving toward high-performance printed electronics.