MoN_(x)薄膜制备及其在柔性不锈钢CIGS太阳电池中的应用

采用反应磁控溅射法制备MoN_(x)薄膜,研究N2流量对MoN_(x)薄膜的结构、形貌、元素组分和光电学特性的影响。通过XRD、SEM、紫外-可见分光光度计等测试,结果表明:当增大N2流量时,薄膜晶相由Mo相向Mo2N相逐渐发生改变,且薄膜的反射率也发生变化,而后利用MoN_(x)薄膜作为抑制Fe等杂质向CIGS薄膜扩散的阻挡层;XRD、SEM结果表明,MoN_(x)薄膜的引入不会影响Mo薄膜、CIGS薄膜晶体结构和形貌;此外,二次离子质谱(SIMS)表明,MoN_(x)阻挡层显著降低了CIGS薄膜中Fe的浓度,最终,将柔性CIGS太阳电池的光电转换效率由10%提升至12.5%。

锂电池MoN_(x)O_(3-x)/C复合材料的制备及其储锂性能的研究

以乙二胺与三氧化钼制备的杂化前驱体作为模板,通过氮气保护下的碳热还原处理,制备出纳米形貌MoN_(x)O_(3-x)/C复合材料,并借助X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)和X射线光电子光谱法(XPS)等手段对材料的结构形貌进行表征。结果表明,通过有机物乙二胺的碳热还原反应,无定形碳原位包覆在氧化钼表面,同时N元素掺杂进入活性组分晶格,这两者的协同效应提升了活性组分的导电性能和晶格稳定性。因此,MoN_(x)O_(3-x)/C表现出良好的电化学性能。在0.05 A/g充放电电流下,样品的首次放电比容量为379 mAh/g,经过80次充放电循环后,放电比容量为229 mAh/g。在0.5和1 A/g的电流条件下,其放电比容量为121和108 mAh/g。

高压下对PtSe_2和二维单层PtSe_2的弹性特性的研究

通过第一性原理计算,研究了60 GPa下块状PtSe_2和二维单层PtSe_2的结构和弹性特性。计算的平衡结构参数与可用的理论结果和使用X射线衍射进行研究的实验数据一致。根据计算出的块状PtSe_2(空间群:P3M1,No:164)和二维单层PtSe_2(空间群:P1,No:1)的力学性能分析,发现两者都符合力学稳定性条件59 GPa(块状PtSe2)和56 GPa(单层PtSe_2)。根据计算的弹性常数,得到了体积模量、剪切模量、杨氏模量以及泊松比。

多层PtSe2/TiO2纳米棒肖特基结紫外光电探测器

提出一种基于多层PtSe2/TiO2纳米棒(NR)阵列的肖特基结紫外光电探测器。多层PtSe2薄膜和TiO2 NRs分别由化学气相沉积法和水热法制备,通过湿转移法,即可获得具有上下结构的多层PtSe2/TiO2 NRs肖特基结器件。光电测试结果表明,所设计的器件对波长为365 nm的紫外光具有较明显的响应,开关比高达5.5×104,响应度和比探测率分别可达57 mA/W和8.36×1011 Jones。此外,器件在空气环境中非常稳定,在空气中放置5周后,光电流基本没有下降。最后,对单个器件的图像传感特性进行研究,结果表明,PtSe2/TiO2探测器可用作图像传感器,能对简单的紫外图形进行成像。

In-situ fabrication of PtSe2/GaN heterojunction for self-powered deep ultraviolet photodetector with ultrahigh current on/off ratio and detectivity

The research of ultraviolet photodetectors(UV PDs)have been attracting extensive attention,due to their important applications in many areas.In this study,PtSe2/GaN heterojunction is in-situ fabricated by synthesis of large-area vertically standing two-dimensional(2D)PtSe2 film on n-GaN substrate.The PtSe2/GaN heterojunction device demonstrates excellent photoresponse properties under illumination by deep UV light of 265 nm at zero bias voltage.Further analysis reveals that a high responsivity of 193 mA·W^-1,an ultrahigh specific detectivity of 3.8 × 10^14 Jones,linear dynamic range of 155d B and current on/off ratio of^10^8,as well as fast response speeds of 45/102μs were obtained at zero bias voltage.Moreover,this device response quickly to the pulse laser of 266 nm with a rise time of 172 ns.Such high-performanee PtSe2/GaN heteroj u nction UV PD demonstrated in this work is far superior to previously reported results,suggesting that it has great potential for deep UV detection.

Morphology-controlled growth of large-area PtSe_(2) films for enhanced hydrogen evolution reaction

Transition metal dichalcogenides(TMDs)have emerged as a promising electrocatalyst for hydrogen evo-lution reaction(HER)due to its excellent conductivity and abundant electrocatalytic active sites of its edges.TMDs nanowall can expose abundant of edges so that they tend to show better catalytic performance for hydrogen evolution reaction.Herein,PtSe_(2) nanowall films with morphology controlled at centimeters level are synthesized by selenizing Pt film.The dynamic and thermodynamics of selenation reaction are investigated.The nanowall structure can be obtained by controlling the growth temperature,and the thickness of nanowall can be tuned by the original thickness of Pt film.The Pt atoms can be rearranged into ordered distribution at 550℃ and can be induced to well-ordered PtSe_(2) nanowalls finally.The well-ordered PtSe_(2) nanowall films show excellent HER performance,with an overpotential of 0.3 V at-10 mA·cm^(-2) and a Tafel slope of~52 mV·dec^(-1).This work demonstrates the great potential of activated 2D PtSe_(2) as an ultrathin film catalyst for the HER,which is valuable to provide instruction and afford experience for further application at industrial level.

Using graphene to suppress the selenization of Pt for controllable fabrication of monolayer PtSe2

Platinum diselenide(PtSe2)is a promising transition metal dichalcogenide(TMDC)material with unique properties.It is necessary to find a controllable fabrication method to bridge PtSe2 with other two-dimensional(2D)materials for practical applications,which has rarely been reported so far.Here,we report that the selenization of Pt(111)can be suppressed to form a Se intercalated layer,instead of a PtSe2 monolayer,by inducing confined conditions with a precoating of graphene.Experiments with graphene-island samples demonstrate that the monolayer PtSe2 can be controllably fabricated only on the bare Pt surface,while the Se intercalated layer is formed underneath graphene,as verified by atomic-resolution observations with scanning transmission electron microscopy(STEM)and scanning tunneling microscopy(STM).In addition,the orientation of the graphene island shows a negligible influence on the Se intercalated layer induced by the graphene coating.By extending the application of 2D confined reactions,this work provides a new method to control the fabrication and pattern 2D materials during the fabrication process.

Growth of large scale PtTe,PtTe_(2) and PtSe_(2) films on a wide range of substrates

1T phase of transition metal dichalcogenides(TMDCs)formed by group 10 transition metals(e.g.Pt,Pd)have attracted increasing interests due to their novel properties and potential device applications.Synthesis of large scale thin films with controlled phase is critical especially considering that these materials have relatively strong interlayer interaction and are difficult to exfoliate.Here we report the growth of centimeter-scale PtTe,1T-PtTe2 and 1T-PtSe2 films via direct deposition of Pt metals followed by tellurization or selenization.We find that by controlling the Te flux,a hitherto-unexplored PtTe phase can also be obtained,which can be further tuned into PtTe2 by high temperature annealing under Te flux.These films with different thickness can be grown on a wide range of substrates,including NaCl which can be further dissolved to obtain free-standing PtTe2 or PtSe2 films.Moreover,a systematic thickness dependent resistivity and Hall conductivity measurements show that distinguished from the semiconducting PtSe2 with hole carriers,PtTe2 and PtTe films are metallic.Our work opens new opportunities for investigating the physical properties and potential applications of group 10 TMDC films and the new monochalcogenide PtTe film.

Glutathione depletion based Pt(Ⅳ) hybrid mesoporous organosilica delivery system to conquer cisplatin chemoresistance: A “one stone three birds” strategy

The occurrence of acquired resistance to cisplatin(DDP)that induces the toxic drug effects has always been a huge challenge and urgently needs to be resolved in the cancer treatment.The combination of anticancer drugs with different mechanisms can remarkably improve the chemotherapeutic efficiency.Given that glutathione(GSH)plays as the driving factors in the resistance of DDP,here we have firstly proposed a“three birds,one stone”based nanoplatform to achieve triple synergetic effects simultaneously addressing DDP resistance in non-small cell lung cancer(NSCLC).Specifically,we initially designed and synthesized a DDP prodrug[Pt(Ⅳ)]bridged silsesquioxane precursor(Pt-Si).Then Pt-Si and bis[3-(triethoxysilyl)propyl]diselenide(BTESe PD)were integrated into the framework of mesoporous organosilica nanoparticles(MONs)to obtain a nanocarrier MONPt/Se.After loading with norcantharidin(NCTD)and modifying with the aptamer AS1411 based G-quadruplex(Apt),the Apt@NCTD@MONPt/Seexhibit impressive tumor homing capability.Once being endocytosed,(Ⅰ)the diselenide and-O-Pt(Ⅳ)-O-rich scaffold can be reduced by the excessive GSH,followed by(Ⅱ)breaking the redox homeostasis via GSH depletion and precise release of the DDP.Next,the encapsulated NCTD is also released along with the degradation of the nanocarriers thereby(Ⅲ)achieving the GSH depletion and synergistic anti-tumor effect of NCTD and DDP.Taken together,we believe this“one stone,three birds”strategy may be a promising paradigm to conquer drug resistance for clinical care.

Shallowing interfacial carrier trap in transition metal dichalcogenide heterostructures with interlayer hybridization

With the unique properties,layered transition metal dichalcogenide(TMD)and its heterostructures exhibit great potential for applications in electronics.The electrical performance,e.g.,contact barrier and resistance to electrodes,of TMD heterostructure devices can be significantly tailored by employing the functional layers,called interlayer engineering.At the interface between different TMD layers,the dangling-bond states normally exist and act as traps against charge carrier flow.In this study,we propose a technique to suppress such carrier trap that uses enhanced interlayer hybridization to saturate dangling-bond states,as demonstrated in a strongly interlayer-coupled monolayer-bilayer PtSe2 heterostructure.The hybridization between the unsaturated states and the interlayer electronic states of PtSe2 significantly reduces the depth of carrier traps at the interface,as corroborated by our scanning tunnelling spectroscopic measurements and density functional theory calculations.The suppressed interfacial trap demonstrates that interlayer saturation may offer an efficient way to relay the charge flow at the interface of TMD heterostructures.Thus,this technique provides an effective way for optimizing the interface contact,the crucial issue exists in two-dimensional electronic community.