Lei Zhou
Soochow University (Taiwan)
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Lei Zhou.
Scientific Reports | 2015
Lei Zhou; Qing-Dong Ou; Jing-De Chen; Su Shen; Jian-Xin Tang; Yan-Qing Li; Shuit-Tong Lee
Organic-based optoelectronic devices, including light-emitting diodes (OLEDs) and solar cells (OSCs) hold great promise as low-cost and large-area electro-optical devices and renewable energy sources. However, further improvement in efficiency remains a daunting challenge due to limited light extraction or absorption in conventional device architectures. Here we report a universal method of optical manipulation of light by integrating a dual-side bio-inspired moths eye nanostructure with broadband anti-reflective and quasi-omnidirectional properties. Light out-coupling efficiency of OLEDs with stacked triple emission units is over 2 times that of a conventional device, resulting in drastic increase in external quantum efficiency and current efficiency to 119.7% and 366u2005cd A−1 without introducing spectral distortion and directionality. Similarly, the light in-coupling efficiency of OSCs is increased 20%, yielding an enhanced power conversion efficiency of 9.33%. We anticipate this method would offer a convenient and scalable way for inexpensive and high-efficiency organic optoelectronic designs.
Journal of Materials Chemistry | 2014
Guangju Zhang; Chuanxi Li; Juan Liu; Lei Zhou; Ruihua Liu; Xiao Han; Hui Huang; Hailiang Hu; Yang Liu; Zhenhui Kang
The Co3O4@N doped carbon (Co3O4@N–C) nanocomposites obtained from metal–organic frameworks (MOFs) possess excellent electrocatalytic ability for oxygen reduction reaction (ORR).
ACS Nano | 2014
Lei Zhou; Heng-Yang Xiang; Su Shen; Yan-Qing Li; Jing-De Chen; Hao-Jun Xie; Irene A. Goldthorpe; L.L. Chen; Shuit-Tong Lee; Jian-Xin Tang
Because of their mechanical flexibility, organic light-emitting diodes (OLEDs) hold great promise as a leading technology for display and lighting applications in wearable electronics. The development of flexible OLEDs requires high-quality transparent conductive electrodes with superior bendability and roll-to-roll manufacturing compatibility to replace indium tin oxide (ITO) anodes. Here, we present a flexible transparent conductor on plastic with embedded silver networks which is used to achieve flexible, highly power-efficient large-area green and white OLEDs. By combining an improved outcoupling structure for simultaneously extracting light in waveguide and substrate modes and reducing the surface plasmonic losses, flexible white OLEDs exhibit a power efficiency of 106 lm W(-1) at 1000 cd m(-2) with angular color stability, which is significantly higher than all other reports of flexible white OLEDs. These results represent an exciting step toward the realization of ITO-free, high-efficiency OLEDs for use in a wide variety of high-performance flexible applications.
ACS Nano | 2016
Lu-Hai Xu; Qing-Dong Ou; Yan-Qing Li; Yi-Bo Zhang; Xin-Dong Zhao; Heng-Yang Xiang; Jing-De Chen; Lei Zhou; Shuit-Tong Lee; Jian-Xin Tang
Flexible organic light-emitting diodes (OLEDs) hold great promise for future bendable display and curved lighting applications. One key challenge of high-performance flexible OLEDs is to develop new flexible transparent conductive electrodes with superior mechanical, electrical, and optical properties. Herein, an effective nanostructured metal/dielectric composite electrode on a plastic substrate is reported by combining a quasi-random outcoupling structure for broadband and angle-independent light outcoupling of white emission with an ultrathin metal alloy film for optimum optical transparency, electrical conduction, and mechanical flexibility. The microcavity effect and surface plasmonic loss can be remarkably reduced in white flexible OLEDs, resulting in a substantial increase in the external quantum efficiency and power efficiency to 47.2% and 112.4 lm W(-1).
ACS Nano | 2015
Heng-Yang Xiang; Yan-Qing Li; Lei Zhou; Hao-Jun Xie; Chi Li; Qing-Dong Ou; L.L. Chen; Chun-Sing Lee; Shuit-Tong Lee; Jian-Xin Tang
Enhancing light outcoupling in flexible organic light-emitting diodes (FOLEDs) is an important task for increasing their efficiencies for display and lighting applications. Here, a strategy for an angularly and spectrally independent boost in light outcoupling of FOLEDs is demonstrated by using plastic substrates with a low refractive index, consisting of a bioinspired optical coupling layer and a transparent conductive electrode composed of a silver network. The good transmittance to full-color emission (>94% over the whole visible wavelength range), ultralow sheet resistance to carrier injection (<5 Ω sq(-1)), and high tolerance to mechanical bending of the ameliorated plastic substrates synergistically optimize the device performance of FOLEDs. The maximum power efficiencies reach 47, 93, 56, and 52 lm W(-1) for red, green, blue, and white emissions, which are competitive with similarly structured OLEDs fabricated on traditional indium-tin-oxide (ITO) glass. This paradigm for light outcoupling enhancement in ITO-free FOLEDs offers additional features and design freedoms for highly efficient flexible optoelectronics in large-scale and low-cost manufacturing without the need for a high-refractive-index plastic substrate.
Journal of Materials Chemistry | 2016
Qing-Dong Ou; Hao-Jun Xie; Jing-De Chen; Lei Zhou; Yan-Qing Li; Jian-Xin Tang
To fully unlock the potential of metallic electrodes in flexible polymer solar cells (PSCs), tuning their optical properties is urgently required. Here we report an efficient light harvesting scheme involving the combination of a silver mesowire grid-based front transparent electrode and a plasmonic meta-mirror-based back reflector electrode. As an alternative to the indium-tin-oxide transparent conductor, the silver mesowire grid on a plastic substrate enables the reduced ohmic loss with competitive mechanical, electrical and optical properties, verifying its superiority in large-area flexible devices. Further implementation of the plasmonic meta-mirror back reflector allows broadband enhancement of light harvesting efficiency over the entire visible wavelength range, yielding a power conversion efficiency of 9.50% due to a 23.2% increase in photocurrent compared to the reference flat device. Experimental and theoretical analysis of light propagation in PSCs elucidates that the optical harvesting enhancement benefits from the synergistic effects of wide-area redistribution of an optical field induced by the silver mesowire grid electrode and broadband recovery of photon loss via surface plasmon and scattering enabled by the meta-mirror back reflector. This method provides a convenient and scalable way for developing high-performance flexible PSCs towards the future photovoltaic applications.
Optoelectronic Devices and Integration V | 2014
Qing-Dong Ou; Lei Zhou; Yan-Qing Li; Jian-Xin Tang
To realize high-efficiency organic light-emitting diodes (OLEDs), it is essential to boost out-coupling efficiency. Here we review our latest reports upon light manipulation for OLEDs by integrating a dual-side bio-inspired deterministic quasi-periodic moth’s eye nanostructure with broadband anti-reflective and quasi-omnidirectional properties. Light out-coupling efficiency of OLEDs with stacked triple emission units is over 2 times that of a conventional device, resulting in drastic increase in external quantum efficiency and current efficiency to 119.7% and 366 cd A-1 without introducing spectral distortion and directionality. Theoretical calculations furthermore clarify that the improved device performance is primarily attributed to the effective extraction of the waveguide and surface plasmonic modes of the confined light over all the emission wavelengths and viewing-angles.
Nanoscale | 2014
Haitao Li; Ruihua Liu; Weiqian Kong; Juan Liu; Yang Liu; Lei Zhou; Xing Zhang; Shuit-Tong Lee; Zhenhui Kang
Advanced Functional Materials | 2015
Lei Zhou; Qing-Dong Ou; Yan-Qing Li; Heng-Yang Xiang; Lu-Hai Xu; Jing-De Chen; Chi Li; Su Shen; Shuit-Tong Lee; Jian-Xin Tang
Materials Research Bulletin | 2016
Dao-cheng Xia; Lei Zhou; Shi Qiao; Yalin Zhang; Di Tang; Juan Liu; Hui Huang; Yang Liu; Zhenhui Kang