- 标题
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- 实验方案
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Boosting the Efficiency and Curtailing the Efficiency Roll-off in Green Perovskite Light-Emitting Diodes via Incorporating Ytterbium as Cathode Interface Layer
摘要： Perovskite light-emitting diodes (PeLEDs) exhibit high external quantum efficiencies (EQEs), emerging as a next-generation technology for lighting and display applications. Nevertheless, they suffer from severe efficiency roll-off at high luminance, particularly in case of blue and green emissions, which is one of the major bottlenecks in their industrial applications. Here, we attack this problem using a rare-earth metal, Yb, as cathode interface layer (CIL) for green PeLEDs. By adopting a new device configuration of ITO/TFB/FA-based Quasi-2D Perovskite/TPBi/Yb/Ag, we achieved a peak current efficiency (CE) of 22.3 cd/A with a corresponding EQE of 5.28% and a high maximum luminance of 19,160 cd/m2. Importantly, the maximum CE of 22 cd/A at 2,000 cd/m2 slightly decreased to 16.8 cd/A at 5,000 cd/m2 and maintained a still decent value of 12 cd/A at a very high luminance of 10,000 cd/m2, exhibiting a remarkably low efficiency roll-off. Our Yb-incorporated devices significantly outperformed the PeLEDs containing conventional CILs, including Mg and Liq, in terms of peak efficiency, efficiency roll-off and operational lifetime. We attribute this encouraging performance to barrier-free, efficient electron injection enabled by the low work function of Yb (2.6 eV) which led to a high electron current, nearly approaching the hole current in hole-dominant PeLEDs, as confirmed by the single-carrier device measurements. In addition, we also present Yb-incorporated PeLEDs containing Cs-based Quasi-2D perovskite as the emissive layer which displayed an impressive CE of 51.3 cd/A with a corresponding EQE of 16.4% and a maximum luminance of 14,240 cd/m2, and still demonstrated a reduced efficiency roll-off comparing to that of the Liq-based equivalent. These results unveil the inspiring prospects of Yb as an efficient CIL for PeLEDs towards high efficiency with reduced efficiency roll-off.
关键词： electron injection,ytterbium,quasi-2D,perovskite light-emitting diodes,stability,cathode interface layer,efficiency roll-off
更新于2025-09-23 15:21:01
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Effect of colloid aggregation characteristic on ZnO interface layer and photovoltaic performance of polymer solar cells
摘要： ZnO as a classical n-type semiconductor oxide is widely used as the electron transport layer for high-efficiency polymer solar cells by using solution processing. To study the effect of ZnO colloid aggregation size on the morphology of ZnO interface layer and photovoltaic performance of polymer solar cells. The ZnO colloid aggregation size was adjusted by aging time, and the PTB7-Th:PC71BM solar cells with various ZnO interface layers were fabricated. The results showed that morphology, structure and property of ZnO interface layer were depended on the ZnO colloid particle size, and then determined the photoelectric performance of the PTB7-Th:PC71BM solar cell. The best performance of PTB7-Th:PC71BM solar cell with 10.21% was obtained when the ZnO precursor solution was set at 2 h aging. The ZnO interface layer with good morphology and appropriate energy level improved the mobility and lifetime of charge carrier. Moreover, it also attributed good interface contact between the ZnO layer and the PTB7-Th:PC71BM active layer, which enhanced the electron transfer and reduced the charge recombination at the interface.
关键词： ZnO colloidal particle size,ZnO interface layer,Polymer solar cells,Aging time,Photovoltaic performance
更新于2025-09-23 15:19:57
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Performance of hybrid energy devices consisting of photovoltaic cells and thermoelectric generators
摘要： The aim of our study on hybrid energy devices (HEDs) is to find out the prerequisites for enhancing the performance of the HEDs using solar energy. In this work, first of all, the performance of the HEDs composed of photovoltaic cells (PVCs) and thermoelectric generators (TEGs) is analyzed, and then the contribution of three different interfaces between the PVC and TEG components to HED performance is assessed under solar irradiance from 200 to 1000 W/m2. The significant result of the analysis emphasizes that the performance of HEDs is enhanced when short-circuit current in HEDs is comparable with the PVCs and the thermoelectric voltage generated by the TEG is large. Furthermore, interfaces with high solar-energy-absorption efficiencies and high thermal conductivity cause TEGs to generate large thermoelectric voltages. Thus, the design of the interfaces plays an important role in enhancing HED performance.
关键词： Hybrid energy device,Photovoltaic,Thermoelectric,Interface layer,Current matching
更新于2025-09-19 17:13:59
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Effect of Interface Layer Engineering on Resistive Switching Characteristics of ZrO?-Based Resistive Switching Devices
摘要： An intentionally introduced interface layer in the resistive random-access memory (RRAM) devices play an important role in the improvement of resistive switching characteristics. In this paper, the resistive switching characteristics of ZrO2-based RRAM devices by inserting a thin TiO2 interface layer between electrodes and ZrO2 resistive switching layer were investigated. Compared with the Cu/ZrO2/Pt and Cu/ZrO2/TiO2/Pt devices, the Cu/TiO2/ZrO2/Pt and Cu/TiO2/ZrO2/TiO2/Pt devices showed much improved programing voltages, including lower forming voltage and lower set voltage. Moreover, the reset current was also improved. These results indicate that the TiO2 interface layer between the anode electrode and the resistive switching layer plays an important role in improving device performance.
关键词： multilayer,Interface layer,resistive random-access memory (RRAM),resistive switching
更新于2025-09-11 14:15:04
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Bi L<sub>III</sub>-Edge XAFS Study of GeBiTe Phase-Change Recording Material Using Actual Media
摘要： The crystallization of GeBiTe (GBT) is faster than that of the well-known phase-change recording material GeSbTe (GST). Therefore, the investigation of GBT structure as well as its crystallization process is attractive. Accordingly, the high-speed crystallization of GBT is due to Bi. Thus, it was necessary to know the local structure around Bi within the amorphous GBT. Note that an interface layer, which is a very thin dielectric film adjacent to recording film, assists the crystallization of phase-change material in the optical recording media. The local structure around Bi in GBT within an actual media was analyzed using XAFS. Bi LIII-edge XAFS spectra of crystalline and amorphous GBT respectively, both with and without interface layer in the media, were obtained. As result of this analysis on GBT, nearest neighbor atom of Bi was found to be Ge. Moreover, within the amorphous GBT, the interatomic distance around Bi is larger than that around Ge. These are the differences between GST and GBT. We speculate that these factors contribute to the improvement of the GBT crystallization speed. On the other hand, the interface layer doesn’t influence the local structure of GBT; however, it does have an electric effect on the recording layer.
关键词： interatomic distance,higher crystallization speed,rewritable optical recording media,Bi LIII-edge,GeSbTe(GST),phase-change material,actual media,EXAFS,interface layer,GeBiTe(GBT)
更新于2025-09-04 15:30:14