The research and development center of electronic functional materials was established in April 2005 at Hubei University, which has four stable scientific research directions, including Micro-nano sensing materials and devices, Energy materials and devices, RRAM, and LED.
Micro-nano sensing materials and devices
In this direction, the center focuses on the research work of ferroelectric nanomaterials and devices, semiconductor sensitive materials and sensors, new medical photoelectric nanomaterials and devices, wireless sensor network, photoelectric functional nanomaterials and FBAR sensors. In recent years, a series of innovative research results have been obtained. Over 140 SCI papers have been published in international important academic journals such as Chem. Rev., J. Mater. Chem., Nanomedicine, J. Hydrogen Energy, Crystal Growth & Design, Appl. Phys. Lett., J. Am. Ceram. Soc.. The center has undertaken 11 national natural science funds, 2 sub-projects of the 863 program of the Ministry of Science and Technology, 3 doctoral funds of the Ministry of Education, and more than 20 provincial and ministerial level projects. The center won 3 second prizes of natural science in hubei province, 1 third prize and 1 first prize of teaching achievements in Hubei province.
The researches of low temperature sintering high power piezoelectric ceramics, high voltage electrical high dielectric piezoelectric ceramics, low electromechanical loss piezoelectric ceramics and large anisotropic piezoelectric ceramics materials have reached the advanced levels at home and abroad.
The high-performance piezoelectric ignition ceramics column researched in cooperation with "Blue ray Electronics Industrial co., LTD." solves the technical problems of easy deterioration and low mechanical strength of the original product, improves its performance and quality, and overcomes the production volume contradiction and low product grade of the enterprise. Low and low profit contradictions. This cooperation project is an agreement of the InternationalTalent Intelligence (Wenzhou) Exchange Conference.
Development and research of new electronic functional materials in cooperation with "Fujian Nan and Hong Wei technology ceramics factory", mainly for the development of high-strength alumina materials. The material has high hardness and high toughness can be widely used in substrates, shaft seals and valve sheets, Grinding balls and mill liners.
Continue to promote the application of "military radar display system YTB4.51.6 type piezoelectric ceramic high voltage switch" and "new military radar CRT display multi-output piezoelectric transformer high voltage converter", To develop a new type of high efficiency, high reliability of radar CRT display high voltage switching power supply, which can be widely used in our army radar along the coast and gun control radar.
Energy materials and devices
In this direction, the center focuses on new type semiconductor nanostructure materials, and solar cells solid oxide fuel cell materials, controllable growth of one-dimensional nanostructures and applications in environmental management, Pt-based alloy - semiconductor composite nanomaterials and photocatalytic hydrogen production. Research work on devices, low dimensional oxide materials etc. The results were published in ACS nano, Chem. Mater, J. Mater. Chem., Scientific Reports, J. Power source, Appl. Catal. B: Environ, Chem.Mater. etc.
The center developed a new method of combining thermal evaporation and electrochemical deposition to prepare the composite electrode of ZnO(nuclear)/CdTe(shell) nanocable array solar cells, which realized the dense deposition of quantum dots on the surface of the nanowires, Stacked deposition greatly improves the saturated nanotubes were used to assemble the "sandwich" structure dye-sensitized solar cell devices as photocurrent of CdTe sensitized ZnO solar cells.on the other hand,a one-dimensional structure of TiO2 nanotubes is used as a photoanode and a high catalytically active Pt pairs prepared by a variety of processes is combined to form a “sandwich” structure dye-sensitized solar cell devices. Further, in order to improve the photoelectric performance of the device, TiO2nanotubes were modified to prepare photoanode of TiO2nanotubes/TiO2nanoparticles, TiO2nanotubes/TiO2nanoparticles/passivating layer and other composite structures. The assembled battery efficiency was as high as 10.3%, which has a good application prospect.
The center uses a sandwich structure as a dense layer to assemble perovskite solar cell devices. The structure of perovskite type solar cell is FTO/ dense layer/mesoporous layer/perovskite CH3NH3PbI3/ hole transport layer (HTM)/Au electrode. The assembled perovskite solar cell has a fill factor reaches 70% and a photoelectric conversion efficiency of 12.6%. The perovskite material and its battery preparation require simple equipment, simple operation process, and low production cost, so it has a good prospect of industrialization.
Pioneering innovative fuel cells (advanced fuel cells with nano-composite functional materials) lead the new direction of development of international fuel cells. In particular, the electrolyte-free single-layer fuel cells invented and developed in 2011 have great scientific foresight and research value.
The wide application of multimedia means puts higher requirements for high performance, low energy consumption and large capacity information storage. Currently widely used type of silicon-based floating gate flash memory in the process of shrinking, because of the influence of the size, it will be unable to effectively the challenge of storing charge, and has inspired researchers to develop new type of storage device. The center has been committed to low dimensional oxide material, such as zinc oxide, nickel oxide, high dielectric materials (hafnium oxide, titanium oxide, antimony oxide, etc.) films and one dimensional structures research. Based on the research of a large number of materials, they are applied to the resistive memory with simple structure and obtain excellent storage performance, which is of great significance for the realization of high-density non-volatile storage in CMOS integrated circuits.
The central team used hafni-based RRAM devices with ITO as the electrode by magnetron sputtering. It is found that the device exhibits the resistance characteristic of "self-limiting current", and the operating voltage can be obtained with the ITO electrode with only 0.3v.This provides a reliable foundation for the development of ultra-low power oxide memory devices. The results were published in the journal Applied Physics Express.
The center mainly studies the performance and storage mechanism of a new class of RRAM materials. It is found that polycrystalline perovskite manganese oxides have huge electro - induced resistivity effect, magnetic and electric double-tuning effect and EPIR effect, especially in NdSrMnO, it is found that the room temperature has a significant and anti-fatigue EPIR effect, which is a kind of RRAM material with good application prospect. Through systematic, detailed experiments and theoretical analysis, it is revealed that the effect is caused by non-intrinsic factors of the material, and it is proved that the effect is caused by the contact between the electrode and the oxide surface of schottky barrier, rather than the interfacial barrier between grains base. In addition, the innovation team conducted fruitful research on the spin characteristics and magnetoresistance of perovskite structure oxides and Hesuler alloy films and heterogeneous interfaces.
The center in the research of super capacitor cooperated with Shiyan Carest Industry &Trade co., LTD. After the modification module, the new electrolyte research, developed the internal resistance of 10-20 mohm, the capacitance of 30-40 F, the rated voltage of 25 and 30 V, charging time of 1.5 s - 3 s (charging current20 A), the use of temperature - 40 ℃ to 60 ℃ inorganic carbon materials super capacitor, the performance is better than a similar product of a company in Shijiazhuang, it has realized the product of A military unit. At present, especially for inorganic super capacitors products, the window for low temperature use is narrow, generally at -20 ℃.We can achieve normal charging at -40 ℃, breaking through the low temperature use limit of inorganic super capacitors, which is of great significance for realizing the smooth ignition of military vehicles in cold conditions. In addition, the group "development and application of very low temperature power type supercapacitors" was funded by the 2014 Nanjing 321 Talent Program.
With the continuous development of the industry, the leap of technology and the promotion of application, LED's luminous efficiency has been constantly improved and the price has been constantly falling. These gradual changes reflect the broad prospect of LED's application in lighting. The center has been committed to the research on the basic properties and material design of new semiconductor photonic devices, the electro-optical, magneto-optical response and quantum control mechanism of semiconductor micro-nano structure, and solved the heat dissipation problem caused by high power density, which is the core problem of LED lighting application.
The center studied an aluminum substrate with high thermal conductivity. The aluminum substrate adopts Al2O3 ceramic membrane as the insulation layer, thus avoiding the use of resin film insulation layer. The key point of this technique is the preparation of Al2O3 ceramic membrane. It adopts electrochemical anodization to form a layer of Al2O3 ceramic film directly on the surface of aluminum plate which has short process and the low cost. The problems that the technology needs to solve include reducing the leakage current of the film layer, improving the pressure resistance, improving the thermal impact resistance and solving the compatibility of the etching process. The overall thermal resistance of aluminum substrate made of ceramic film is 0.3-0.5 kcm2/W, which is the highest standard CALD of CPCA2010.Growth of ultra-thick ceramic films: the film thickness can be up to more than 110 microns, and the pressure resistance value of the film layer is up to 6 kV. High electrical strength film growth: over 110V/um. High dense ceramic membranes: low leakage current, resistivity exceeding more than 106 M Ω cm. High toughness ceramic film: aluminum substrate is resistant to 260 degrees of thermal shock, drilling, punching, milling, and other machining.
The technology achievement transformation and market promotion of GaN based semiconductor lighting devices have been supported by many industrialization projects and talent projects, achieving an output value of tens of millions of Yuan, which has been beneficial in the industrialization and marketization of optoelectronic frontier technology.
The design, application and cross-over research of new type of semiconductor all-optical information processing device is a major application demand in the field of optoelectronic technology in the next decade. It needs to strengthen the "industry-university-research" cooperation to open up the transformation channel, which can provide good support for the research on new type of semiconductor materials and the mechanism of optical quantum control.