The effect of Au nanorods （NRs） on optical-to-electric conversion efficiency is investigated in inverted polymer solar cells, in which Au NRs are sandwiched between two layers of ZnO. Accompanied by the optimization of thickness of ZnO covered on Au NRs, a high-power conversion efficiency of 3.60% and an enhanced short-circuit current density （Jsc） of 10.87 mA/cm2 are achieved in the poly（3-hexylthiophene）： [6,6]-phenyl-C61-butyric acid methyl ester （P3HT：PC60BM）- based inverted cell and the power conversion efficiency （PCE） is enhanced by 19.6% compared with the control device. The detailed analyses of the light absorption characteristics, the simulated scattering induced by Au NRs, and the electromag- netic field around Au NRs show that the absorption improvement in the photoactive layer due to the light scattering from the longitudinal axis and the near-field increase around Au NRs induced by localized surface plasmon resonance plays a key role in enhancing the performances.
Enhancement of open-circuit voltage(Voc)is an effective way to improve power conversion efficiency(PCE)of the perovskite solar cells(PSCs).Theoretically,work function engineering of TiO2 electron transport layer can reduce both the loss of Voc and current hysteresis in PSCs.In this work,two-dimensional g-C_(3)N_(4) nanosheets were adopted to modify the compact TiO2 layers in planar PSCs,which can finely tune the work function(WF)and further improve the energy level alignment at the interface to enhance the Voc and diminish the hysteresis.Meanwhile,the quality of perovskite films and charge transfer of the devices were improved by g-C_(3)N_(4) nanosheets.Therefore,the PCE of the planar PSCs was champed to 19.55%without obvious hysteresis compared with the initial 15.81%,mainly owing to the remarkable improvement of VOC from 1.01 to 1.11 V.In addition,the stability of the devices was obviously improved.The results demonstrate an effective strategy of W_(F) engineering to enhance Voc and diminish hysteresis phenomenon for improving the performance of PSCs.
Jian YangLiang ChuRuiyuan HuWei LiuNanjing LiuYuhui MaWaqar AhmadXing’ao Li
Organometallic halide perovskite materials make great achievements in optoelectronic fields,especially in solar cells,in which the organic cations contain amine components.However,the amine with NàH bonds is easily hydrolyzed with moisture in the air,weakening the perovskite materials stability.It is desirable to develop other non-amine stable perovskite materials.In this work,sulfur-based perovskite-like(CH_(3))_(3)SPbI_(3) nanorod arrays were fabricated by a solution-processed method,which can be indexed hexagonal crystal structure in the space group P63 mc.The binding force is exceptionally strong between the non-amine(CH_(3))_(3) S+and[PbI_(6)]_(4)-octahedral,leading to high stability of(CH_(3))_(3)SPbI_(3).The(CH_(3))_(3)SPbI_(3) nanorod arrays can keep the morphology and crystal structure in an ambient atmosphere over 60 days.In addition,the(CH_(3))_(3)SPbI_(3) nanorod arrays can offer direct charge transfer channels,which show excellent optoelectronic properties.The(CH_(3))_(3)SPbI_(3) nanorod arrays-based solar cells with VOx hole transfer layers achieved a power conversion efficiency of 2.07%with negligible hysteresis.And the(CH_(3))_(3)SPbI_(3) nanorod arrays were also effectively applied in photodetectors with interdigitated gold electrodes.This work demonstrates that sulfur-based perovskite-like(CH_(3))_(3)SPbI_(3) is a novel promising stable compound with great potential for practical optoelectronic applications.
Lead-based halide perovskites have emerged as excellent semiconductors for a broad range of optoelectronic applications, such as photovoltaics, lighting, lasing and photon detection. However, toxicity of lead and poor stability still represent significant challenges. Fortunately, halide double perovskite materials with formula of A_2M(I)M(III)X_6 or A_2M(IV)X_6 could be potentially regarded as stable and green alternatives for optoelectronic applications, where two divalent lead ions are substituted by combining one monovalent and one trivalent ions, or one tetravalent ion. Here, the article provides an up-to-date review on the developments of halide double perovskite materials and their related optoelectronic applications including photodetectors, X-ray detectors, photocatalyst, light-emitting diodes and solar cells. The synthesized halide double perovskite materials exhibit exceptional stability, and a few possess superior optoelectronic properties. However, the number of synthesized halide double perovskites is limited, and more limited materials have been developed for optoelectronic applications to date. In addition, the band structures and carrier transport properties of the materials are still not desired, and the films still manifest low quality for photovoltaic applications. Therefore, we propose that continuing e orts are needed to develop more halide double perovskites, modulate the properties and grow high-quality films, with the aim of opening the wild practical applications.
Liang ChuWaqar AhmadWei LiuJian YangRui ZhangYan SunJianping YangXing'ao Li
Au nanoparticles （NPs） mixed with a majority of bone-like, rod, and cube shapes and a minority of irregu- lar spheres, which can generate a wide absorption spectrum of 400 nm-1000 nm and three localized surface plas- mon resonance peaks, respectively, at 525, 575, and 775 nrn, are introduced into the hole extraction layer poly（3,4- ethylenedioxythiophene）：poly（4-styrenesulfonate） （PEDOT：PSS） to improve optical-to-electrical conversion performances in polymer photovoltaic ceils. With the doping concentration of Au NPs optimized, the cell performance is significantly improved： the short-circuit current density and power conversion efficiency of the poly（3-hexylthiophene）： [6,6]-phenyl- C60-butyric acid methyl ester cell are increased by 20.54% and 21.2%, reaching 11.15 mA.cm-2 and 4.23%. The variations of optical, electrical, and morphology with the incorporation of Au NPs in the cells are analyzed in detail, and our results demonstrate that the cell performance improvement can be attributed to a synergistic reaction, including： 1） both the local- ized surface plasmon resonanceand scattering-induced absorption enhancement of the active layer, 2） Au doping-induced hole transport/extraction ability enhancement, and 3） large interface roughness-induced efficient exciton dissociation and hole collection.
