Nanomaterials
·
2022
·Vol. 12
·期 9
·1454
·
IF 5.719
Lufeng Hu,Zhixiang Ye,Dan Wu,Zhaojin Wang,Weigao Wang,Kai Wang,Xiangqian Cui,Ning Wang,Hongyu An,Bobo Li,Bingxi Xiang,Mingxia Qiu
Highly luminescent FAPb0.7Sn0.3Br3nanocrystals with an average photoluminescence (PL) quantum yield of 92% were synthesized by the ligand-assisted reprecipitation method. The 41-nm-thick perovskite film with a smooth surface and strong PL intensity was proven to be a suitable luminescent layer for perovskite light-emitting diodes (PeLEDs). Electrical tests indicate that the double hole-transport layers (HTLs) played an important role in improving the electrical-to-optical conversion efficiency of PeLEDs due to their cascade-like level alignment. The PeLED based on poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,40-(N-(p-butylphenyl))-diphenylamine)] (TFB)/poly(9-vinylcarbazole) (PVK) double HTLs produced a high external quantum efficiency (EQE) of 9%, which was improved by approximately 10.9 and 5.14 times when compared with single HTL PVK or the TFB device, respectively. The enhancement of the hole transmission capacity by TFB/PVK double HTLs was confirmed by the hole-only device and was responsible for the dramatic EQE improvement.Keywords:perovskite light-emitting diode;FAPb0.7Sn0.3Br3film;double hole transport structure;light-emitting layer thickness
研究领域:
材料科学
·
光电设备
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2024
·Vol. 20
·期 48
·2405528
·
IF 13
Lunyao Pan,Xiankan Zeng,Yuanxiao Qu,Maolin Mu,Shiyu Yang,Yongjian Chen,Chenglong Li,Linzhu Dai,Li Tao,Hongqiang Xin,Wen Li,Weiqing Yang
Cu 2 ZnSnS 4 (CZTS) is strong candidate for hole transport in perovskite light emitting diodes (PeLEDs) due to their cost-effectiveness, deep highest occupied molecular orbital (HOMO), and high hole mobility. However, its inherent polymetallic ions usually deteriorate the quality of the perovskite emission layer (EML) affecting device performance. In this study, a bidirectional anchoring strategy is proposed by adding 15-crown-5 ether (15C5) into CZTS hole transport layer (HTL) to suppress the reaction between HTL and EML. The 15C5 molecule interacts with Cu + , Zn 2+ and Sn 2+ cations forming host–guest complexes to impede their migration, which is elucidated by density functional theory calculations. Additionally, 15C5 can neutralize lead (Pb) defects by the abundant oxygen (O) and high electronegative cavities to reduce the nonradiative recombination of FAPbBr 3 film. This bidirectional anchoring strategy effectively improves hole charge transport efficiency and suppresses nonradiative recombination at the HTL/EML interface. As a result, the optimized PeLEDs present a 3.5 times peak external quantum efficiency (EQE) from 3.12% to 11.08% and the maximum luminance ( L max ) increased from 24495 to 50584 cd m −2 . These findings offer innovative insights into addressing the metal ion migration issue commonly observed in inorganic HTLs.
研究领域:
材料科学
·
光电子学
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半导体物理
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产品关联
DOI
PubMed
高影响因子
npj Flexible Electronics
·
2024
·Vol. 8
·期 1
·1-8
·
IF 12.3
Zhang Jiaxue,Lu Qianying,Wu Ming,Sun Yuping,Wang Shaolei,Wang Xiaoliang,Lu Ming-Hui,Kong Desheng
Stretchable displays that combine light-emitting capabilities with mechanical compliance are essential building blocks of next-generation wearable electronics. However, their widespread applications are currently limited by complex device architecture, limited pixel density, and immature fabrication processes. In this study, we present the device design and material developments of intrinsically stretchable light-emitting drawing displays that can show arbitrary hand-drawing features. The alternating-current electroluminescent display uses a simplified architecture comprising coplanar interdigitated liquid metal electrodes, an electroluminescent layer, and a dielectric encapsulation layer. Ink patterns on the device are coupled with the interdigitated electrodes under alternating voltage stimulations, generating localized electric fields for bright emissions. Various inks are prepared for painting, stamping, and stencil printing. Arbitrary luminous features on the devices can be either long-lasting or transient in characteristics. These skin-like devices are made entirely of compliant materials that can withstand bending, twisting, and stretching manipulations. Due to the excellent mechanical deformability, the drawing displays can be conformally laminated on the skin as body-integrated optoelectronic communication devices for graphic information.
研究领域:
材料科学
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电子工程
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可穿戴技术
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光电子学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yongjian Chen,Xiankan Zeng,Cheng Yan,Shiyu Yang,Lunyao Pan,Chenglong Li,Maolin Mu,Wen Li,Guanqi Tang,Weiqing Yang
Charge carriers will recombine outside the emitting layer (EML) in non-ideal perovskite light-emitting diodes (PeLEDs), which can lead to parasitic loss and be detrimental to the performance of PeLEDs. Here, we have subtly utilized the property of perovskite nanocrystals (NCs) to design and optimize the homogeneity and optical property of EML, thereby suppressing the undesired carrier loss behavior in system. Photoluminescence (PL) spectra with transmission electron microscopy (TEM) images show that smaller and more homogeneous NCs in size are obtained by temperature-controlled (TC) method. Atomic force microscopy (AFM) images and temperature-dependent PL spectra show that EML with better optical property and uniformity is fabricated. The multiscale capacitance characterization shows that the device with modified EML exhibits significantly reduced leakage current, while the increased specific surface area between electron transport layer (ETL) and EML substantially reduces charge accumulation. Additionally, multiscale reactance, impedance and phase angle responses, reveal that the carrier oscillation behavior in the optimized device is suppressed compared to control group, leading to less energy loss. Consequently, the optimized devices exhibit lower leakage current and superior electroluminescent properties. The luminance is increased from 31650 cd/m 2 to 72941 cd/m 2 , current efficiency (CE) is improved from 59.9 cd/A to 94.3 cd/A, and the external quantum efficiency (EQE) rises from 12.6 % to 19.7 %, corresponding to improvement of 230 %, 157 %, and 156 %, respectively. This research provides valuable insight into the impact of functional layer morphology on carrier dynamic behavior in PeLEDs.
研究领域:
材料科学
·
光电技术
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纳米技术
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半导体物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）