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High-Performance Photodetector Based on Graphene Quantum Dot/CH3NH3PbI3 Perovskite Hybrid
摘要： Organometallic perovskites have great potential for their utilization in photodetector. However, the photoresponsivity of the perovskite film is limited by the low light absorption and charge transport capability. The preparation of good quality film with higher light–harvesting capability on the substrate has been a challenging job till now. In this work, we have developed high–quality white fluorescence graphene quantum dots and CH3NH3PbI3 hybrid film by one–step solvent–induced fast deposition–crystallization technique for the photodetector applications. Various amount of graphene quantum dots is added in composites to optimize the device performance and the hybrid film results in smooth and compactly distributed crystalline grains. The hybrid film device has exhibited 2 times higher photocurrent–to–dark current ratio, three–fold improved responsivity of 12 A W-1, detectivity enhancement upto 6.5 × 1011 Jones and a faster response speed compare to that of the neat MAPbI3 at -3 V bias voltage. The graphene quantum dots addition induces efficient charge transfer and enhances the photocurrent by more than 2 times compare to the neat film. High light absorption and fast charge transport capability of the film are the primary responsible for the high performance of the photodetector.
关键词： Photodetector,Graphene quantum dot,High–quality film,Fast deposition crystallization,CH3NH3PbI3 perovskite
更新于2025-09-12 10:27:22
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BiFeO3/CH3NH3PbI3 Perovskite Heterojunction Based Near-Infrared Photodetector
摘要： The paper reports a hybrid (i.e. organic-inorganic) perovskite CH3NH3PbI3 and inorganic only perovskite BiFeO3 based heterojunction diode for near-infrared detection applications. The hybrid halide CH3NH3PbI3 is synthesized by using sol-gel chemical route while the BiFeO3 is synthesized by using a solid-state route. A layer of uniformly distributed BiFeO3 thin film is first grown on an indium doped tin oxide (ITO) coated glass substrate using BiFeO3 nanoparticles with an average size of ~65 nm. Then, CH3NH3PbI3 nanoparticles of average size ~45 nm with a tetragonal phase are deposited BiFeO3 film for fabricating the heterojunction device under study. The photoresponse is measured by using a monochromatic light over the wavelengths from 400 to 900 nm. The device shows a dual-band photoresponsivity originated from the individual absorption characteristics of BiFeO3 and CH3NH3PbI3 the heterojunction. The proposed photodetector shows the maximum responsivity of ~2 A/W at 800 nm for 2 V bias while the detectivity is estimated as ~7.8×1012 cmHz1/2/W. The photodetector has a reasonably good photoresponse with a rise time and fall time of 0.74 s and 0.088 s, respectively.
关键词： Photodetector,Heterojunction,Responsivity,BiFeO3,Perovskite,CH3NH3PbI3
更新于2025-09-11 14:15:04
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A 3D hybrid nanowire/microcuboid optoelectronic electrode for maximised light harvesting in perovskite solar cells
摘要： A high-performance optoelectronic device requires efficient light harvesting and management in the electrodes. In this work, we report the integration of antireflective anatase TiO2 nanowire (TNW) arrays and CH3NH3PbI3 microcuboid (CMC) film into a new bilayer architecture. The highly porous and well-interconnected anatase TNW arrays showcase antireflective properties for enhanced light transmittance and provide a largely accessible surface area for anchoring the perovskite light absorber. The thick and compact CMC film enables efficient light absorption. Thus, perovskite solar cells (PSCs) fabricated with a hybrid TNW/CMC optoelectronic electrode achieved an optimal power conversion efficiency (PCE) of up to 20.1% under one sun illumination with a high Jsc of 23.2 mA cm?2, which can be attributed to the maximised light harvesting efficiency within the devices.
关键词： light harvesting,perovskite solar cells,CH3NH3PbI3 microcuboid,optoelectronic electrode,TiO2 nanowire
更新于2025-09-11 14:15:04
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A Bi <sub/>2</sub> Te <sub/>3</sub> Topological Insulator as a New and Outstanding Counter Electrode Material for High-Efficiency and Endurable Flexible Perovskite Solar Cells
摘要： Inverted flexible perovskite solar cells (PSCs) typically employ expensive metals as the counter electrodes, which are brittle and corrodible by perovskite, leading to a sharp performance drop under continuous bending, air exposure, thermal stress or light illumination and eventually retards the commercialization. Herein, a low-cost Bi2Te3 counter electrode was employed by using a simple thermal evaporation process. The resultant device achieved an excellent power conversion efficiency of 18.16%, which was among the highest reported efficiencies, much higher than the reference Ag PSC (15.90%). The improvement should be attributed to the intrinsic suppressed electron backscattering in Bi2Te3 topological insulator. Simultaneously, the Bi2Te3 device obtained a significantly improved mechanical flexibility and long-term operational stability. The present strategy will help to open up a new avenue for future commercialization of flexible photovoltaic applications.
关键词： Topological insulator,Bi2Te3,Flexible perovskite solar cells,Counter electrode,CH3NH3PbI3
更新于2025-09-11 14:15:04
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Numerical simulation of carrier transporting layer free planar perovskite cells
摘要： One of challenging issues in research on planar perovskite solar cells (PSCs) is to design a device structure as simple as possible with high device performance, being beneficial to decreasing process complexity, improving device stability and reducing fabrication cost. In this work, concerning two categories of configurations, p-CH3NH3PbI3 based hole transporting layer (HTL) free planar PSCs, as well as p-CH3NH3PbI3 based HTL- free and electron transporting layer (ETL) free planar PSCs were modeled and simulated by AFORS-HET software, and the performances of these PSCs were analyzed in detail. Several factors or parameters that influence the performance of PSCs were concerned in the models, such as interface defect layer, trap density of the perovskite layer, series resistance and shunt resistance. The yielded power conversion efficiency (PCE) of HTL-free PSCs with the configurations of ZnO:Al/ZnO/CH3NH3PbI3 and ZnO:Al/TiO2/CH3NH3PbI3 were 14.36% and 16.92%, respectively. Three transparent conductive oxide (TCO) materials, i.e. ZnO:Al, FTO and ITO, were directly combined with p-type CH3NH3PbI3 to form ZnO:Al/CH3NH3PbI3, FTO/CH3NH3PbI3 and ITO/CH3NH3PbI3 carrier transporting layer free PSCs, with the PCE up to 15.91%, 15.48% and 6.42%, respectively. This evaluation indicates the high performances of some both HTL-free and ETL-free, carrier transporting layer free, planar PSCs with TCO/perovskite heterojunctions, an extremely simple device structure. This could be because photo-generated carriers can be effectively separated by built-in electric field and transported from p-n heterojunctions to electrodes in TCO/CH3NH3PbI3 heterojunction solar cells.
关键词： Planar perovskite solar cells,HTL-free,Power conversion efficiency,TCO/ETL/CH3NH3PbI3,TCO/CH3NH3PbI3,ETL-free
更新于2025-09-10 09:29:36
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Formation of CH <sub/>3</sub> NH <sub/>2</sub> -incorporated intermediate state in CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> hybrid perovskite thin film formed by sequential vacuum evaporation
摘要： CH3NH3PbI3 thin films were formed with various deposition rates of PbI2 first layer using a sequential vacuum evaporation method (SVE) to understand the formation behavior. Under low PbI2 deposition rates with 1 and 3 ? s?1, the thin films did not form the hybrid perovskite structure. Over the 6 ? s?1 deposition rate, the perovskite structure is observed with the remaining PbI2 and an intermediate phase together. In the 10 ? s?1, the intermediate phase is increased, and the CH3NH2 molecular defect is observed. The hybrid perovskite thin film formed by SVE is confirmed with tiny grains and CH3NH2-incorporated intermediate state.
关键词： CH3NH3PbI3,intermediate phase,CH3NH2 molecular defect,sequential vacuum evaporation,hybrid perovskite
更新于2025-09-10 09:29:36
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Understanding Interactions between Lead Iodide Perovskite Surfaces and Lithium Polysulfide toward New-Generation Integrated Solar-Powered Lithium Battery: an ab-Initio Investigation
摘要： Energy conversion devices such as perovskite solar cells and energy storage devices such as lithium sulfur battery flourish in these decades owing to their capabilities to deliver large power conversion efficiency and store superior specific energy, with potentials to solve the global energy crisis and environmental issues. Compared with conventional energy conversion devices and energy storage devices that have limited performances, integrating the energy conversion devices and energy storage devices into a single unit is advantageous to present enhanced performance in multiple applications and satisfy the commercial needs. However, further development of the integration relies on a deeper understanding of the interactions between the functional materials in the energy conversion devices and energy storage devices. In this study, we try to bridge the gap by investigating the interactions between the light absorbing halide perovskite material CH3NH3PbI3 and the lithium polysulfide intermediates (S8, Li2S8, Li2S6, Li2S4, Li2S2 and Li2S) formed during the charging/discharging processes in lithium sulfur batteries via ab-initio calculations. We find that the CH3NH3PbI3 and lithium polysulfide species have decent interactions, with the lithium polysulfide species residing stably on the halide perovskite surfaces and such interactions are strengthened by the charge transfer characters between the adsorbates and the adsorbents. We propose that the light absorbing halide perovskite materials represented by the CH3NH3PbI3 absorber exhibit potentials to be integrated into the lithium sulfur battery cathode to serve as an anchoring material to harness the solar power and mitigate the battery degradation problem, since the dissolution of intermediate lithium polysulfide (Li2Sn) is a severe problem in lithium sulfur batteries. The resulting integrated device is superior in capturing the solar energy due to the presence of the halide perovskite moiety and exhibits a large specific energy, low cost and low toxicity due to the sulfur materials. The comprehensive understanding of the light absorbing halide perovskite material and the lithium polysulfide species in this theoretical work forms a foundation for the further development and commercialization of integrated device that captures solar energy and can be charged/discharged efficiently.
关键词： perovskite solar cells,energy storage,energy conversion,integrated device,lithium polysulfide,lithium sulfur battery,ab-initio calculations,CH3NH3PbI3
更新于2025-09-04 15:30:14