News on China's scientific and technological development.

Recently, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (SINANO) developed a normally off AlGaN/GaN/Si HEMT power switching device. The device shows good gate input swing of 15 Volt and high threshold voltage of 3.5 Volt, which has reached the international advance level. It is also the first time in China that the GaN/Si power switching device is reported.

Owing to the excellent material properties such as high electron mobility and high breakdown field, GaN-based semiconductors are well suited for next-generation power switching devices. It is expected that the power conversion systems using GaN power switches can achieve 3.5% to 7% efficiency improvement with volume shrinkage of about 35%. Recent progress in GaN epitaxial growth technology allowed the fabrication of GaN-on-Si wafers with high quality, low cost, and large wafer size of up to six inch. Based on the GaN-on-Si technology platform, field-effect transistors (FETs) can be produced in large volume. Many world famous power devices manufacturers such as, IR, Infineon, Fairchild, Samsung are focusing on development of GaN/Si power switches. According to Yolo’s analysis, the market of GaN power devices will reaches 0.35 billion USD in 2015, then increase sharply in the following several years. In the next decade, GaN power device will become a strong competitor to traditional Si power device, and share discrete power devices market of ten billion USD per year currently.

Fabrication of GaN/Si power switching device is really a tough work, including material epi-growth, chip process and package. Many technical barriers need to be overcome, for instance, high quality GaN epi-growth on large Si substrate, normally off operation with higher threshold voltage more than 3V and large gate input swing. Though small devices have already been demonstrated by many research teams all around the world, however, few companies could show large devices with high current more than five ampere owing to the sophisticated process controlling.

SINANO started the GaN/Si high power switching devices from 2010. The team invited Professor Kevin J. Chen of HKUST as technical consultant, who is a famous scientist in compound semiconductor devices. They also had cooperation with Suzhou Silikron Semiconductor Company. By overcoming the key technical problems and developing some unique technologies, the threshold voltage of the power switching devices reaches 3.5 Volt, maximum output current reaches 5.3 Amp, and pinch-off breakdown voltage reaches 402 Volt. It should be noted that this device shows good gate input swing (15 Volt). The high threshold voltage of 3.5 Volt and large gate input swing of 15 Volt enable the direct replacement of traditional Si power devices by this device in power conversion systems.

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Cooling down the cost bubble

"Although there exist many problems, the development and scale of China's photovoltaic industry is still something to be proud of", said Xu Honghua, a researcher of the Institute of Electrical Engineering of the Chinese Academy of Sciences. Xu Honghua suggested that China was gradually becoming one of the most important countries of the world's photovoltaic industry.

Last year, the production capacities of China's silicon wafer, battery, and module have all exceeded 410 million watts, an increase of 100 percent over the previous year, accounting for about 60 percent of total global output. In the meantime, China exported approximately 16 GW of solar energy battery, the export value being US$ 25 billion. Mainland China has four of the world's top ten polycrystalline silicon companies, and six of the world's top ten silicon wafer companies.

Last October, the USA announced that it would carry out anti-dumping and anti-subsidy investigation on China's crystalline silicon photovoltaic batteries, and initial result was published in March this year which asserted that related Chinese photovoltaic companies had received "unfair subsidy" from the government. Meanwhile, subsidies to photovoltaic energy generation in many European countries that are the world's major photovoltaic markets have been significantly reduced or even cancelled.

These multiple blows chill China's photovoltaic industry. There are cries across the industry that "winter has come".

However, for the overheated photovoltaic industry, a "winter" may not be as bad as it seems. Take price for example, the chill cools down the power generation cost that has been inflated by high profit. In the spot market, the price of polycrystalline silicon was at one point as high as US$ 500/kg in 2008, but now the price is only around US$ 20/kg. People in the industry said that "this is not shrinking, but dehydrating".

"One good thing about the rapid slip in the price of the silicon supply chain is that it would accelerate the realization of par grid connection", said chief photovoltaic industry analyst of the famous solar energy analysis organization HIS-iSuppli.

Zhu Gongshan, chairman of the board of GCL-Poly Energy Holdings, believes that under the pressure of the collapse of price, the development of photovoltaic enterprises are switching from reliance on volume and capacity expansion to reliance on scientific advancement and cost reduction. The process of photovoltaic power generation going to ordinary household is being accelerated.

It's encouraging that in the meantime of cost reduction, the conversion rate of photovoltaic power generation is improving significantly. "At present, we can see that the downward curve of the production cost of photovoltaic products is very obvious. Meanwhile, the conversion rate of solar energy production has increased from 10 percent to 15 percent, with some even reaching 18 percent", said a person From Narada.

"In the recession of the industry, the significant price reduction of photovoltaic products results in the significant cost reduction of photovoltaic power generation. The critical point to par grid connection is getting nearer", said Shi Zhengrong, chairman of the board of Suntech.

With continuously maturing and improving technology and the large-scale development of the manufacturing industry, the cost of photovoltaic modules that account for half of the cost of the entire system has been reduced by more than 50 percent since 2007 at an annual rate of 20 percent.

Experts are very confident about the prospects of the photovoltaic industry: ten years ago, the cost of photovoltaic power generation was as high as RMB 5 Yuan/kwh; now, the cost is lower than RMB 1 Yuan/kwh. It is estimated that photovoltaic power generation cost may be reduced to as low as RMB 0.3 or 0.4 Yuan/kwh in 5 years.

Subsidy is no longer a necessity

Because currently the cost of photovoltaic power generation is higher than conventional power generational, many countries have been subsidizing photovoltaic power generations in various ways so as to compensate companies' loss. Presently, some main countries adopt similar subsidy policy. The electricity price subsidies in all states of America, and the FiT subsidy in Germany, Italy and Japan are all at an appropriate amount after calculating the difference between the costs of the two types of power generation.

Subsidy, however, is a double-edged sword. While it can promote the development of the photovoltaic industry, it can also hinder its "independent" development following market rules. Photovoltaic power generation's par connection to the grid can break this development restriction once and for all.

The Development Plan of the Photovoltaic Industry during the 12th Five-year Plan published not long ago in China specially proposes the "goal of photovoltaic power generation cost", which is the core of the whole plan. According to the goal, in 2015, the cost of photovoltaic system will be reduced to RMB 15,000 Yuan/kw, power generation cost will be reduced to RMB 0.8 Yuan/kwh, and par grid connection will be achieved on the power distribution end; in 2020, the system cost will be reduced to RMB 10,000 Yuan/kw, power generation cost will be reduced to RMB 0.6 Yuan/kwh, par grid connection will achieved on the power generation end, and solid competitiveness will be achieved in major electricity power market.

"What does it mean when the cost of generating one kwh reduced to RMB 0.8 Yuan? It means that par grid connection is achieved on the user end. Now in big cities such as Beijing, Shanghai, and Guangzhou, the price of one kwh of electricity for industrial and commercial use is RMB 1.1 Yuan. If the cost of photovoltaic power generation is only RMB 0.8 Yuan in 2015, photovoltaic power generation will be able to yield profit, and the user end doesn't need government subsidy. And in 2020, the target power generation cost is RMB 0.6 Yuan. The price of thermal power generation may exceed RMB 0.6 Yuan in the year 2020. Therefore, if the price of photovoltaic power generation can be reduced to below RMB 0.6 at that time, it would mean that no subsidy is needed on the power station side", said Meng Xiangan, deputy chairman of China Renewable Energies Society.

Industrial experts believe that par grid connection can be achieved in two phase, namely replacing conventional fossil energies on the user end in the short term and replacing conventional energies on the power generation end in the long term.

From the perspective of the short-term goal, the price of electricity, the conventional energy, is relatively higher in sunny regions and in areas where power-grid construction is weak, such as the northwestern region of China, Africa, and the western coastlines of America, due to such factors as geographical location and transportation. In these places, photovoltaic power generation is fully capable of competing directly with conventional energies. Therefore, it's necessary to develop small-household (off-grid) system selectively, optimize such aspects as module power, installation method, and choice of inverter, and increase effort in market promotion and improvement of sales and after-sales channel. The aim is to make it not only affordable to users, but also accessible and available.

As for the long-term goal, the aim is to replace conventional energies with photovoltaic power generation on the power generation end in large scale, and consequently solve the global energy crisis and climate and environment crisis once and for all. To achieve that, we need to not only make effort in management and cost control, but also continue to renovate technology, improve battery efficiency, improve module power, optimize the efficiency of power station system, and lower the cost of each kwh.

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Researchers with the Institute of Process Engineering, Chinese Academy of Sciences made an overview on the CO2 capture with ion liquids, a promising technology which has made significant progress recently, and clarified the research goal of this technology.

The latest research on the CO2 separation, CO2 capture mechanisms as well as transport properties and hydrodynamics of ionic liquid fluids were discussed with more focus on the potential industrial applications. Some perspectives of the novel technologies and challenges in future were present.

Researchers investigated and compared CO2 absorption performance of conventional ionic liquids, task-specific ionic liquids and ionic liquid mixture solvents. Based on the results of experiments, they clarified that the main task of future work is to design new ionic liquids or mixtures with high gravimetric CO2 capacity, high selectivity, and lower viscosity so as to improve the competitive edge of ionic liquids solvents. However, one of the big challenges is how to screen the suitable ionic liquids from numerous candidates.

The capture mechanisms of chemisorption and physisorption were explained with experimental characteristics and molecular simulation, which showed more and more importance on screening suitable ionic liquids from tremendous candidates.

Studies on the transport and the fluid dynamic property as well as the process design of ionic liquid-based carbon capture process were reviewed considering scaling-up application. Based on what mentioned above, they concluded that the transport properties and hydrodynamics as well as kinetics of IL-based CO2 capture systems should be studied both in respect of experimental measurement and CFD calculation in order to obtain the optimal structure and the size of each unit. In addition, process simulation and related thermodynamic models and phase equilibrium should be paid attention to.

Among the emerging technologies, capturing CO2 with ionic liquids is a promising way to overcome current drawbacks due to their unique properties, such as negligible vapor pressures, high thermal stability, strong solubility capacity and tunability of structure and property. In the coming decades, addressing climate change concerns will likely require significant contributions from CO2 capture.

The paper was published in Energy & Environmental Science

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The Tomato Genome Consortium (TGC), a group of over 300 scientists from fourteencountries, has sequenced the genomes of the domesticated tomato and its wild ancestor, Solanum pimpinellifolium. This achievement, which was published as a cover story in the May 31 issue of Nature, is expected to lower costs and speed up efforts to improve the world-wide tomato production, making it better equipped to combat the pests, pathogens, drought and diseases that now plague growers. The work may also speed up improvements inother crops.

China contributed sequencing chromosome 3 and 11, two of the tomato’s 12 chromosomes. The chromosome 3 team was led by professors Chuanyou Li and Yongbiao Xue from the Institute of Genetics & Developmental Biology (IGDB), Chinese Academy of Sciences. Thirty-four scientists from 8 institutions contributed the chromosome 3 sequencing effort. The Chromosome 11 team was led by professors Sanwen Huang and Yongchen Du from the Institute of flowers and vegetables, Chinese Academy of Agricultural Sciences. Twenty-two scientists from 7 institutions contributed the chromosome 11 sequencing effort.　

Together, the sequences provide the most detailed look at the functional portions of the tomato genome, revealing the order, orientation, types and relative positions of its 35,000 genes. Tomato is a member of the Solanaceae or nightshade family, and the new sequences are expected to provide reference points helpful for identifying important genes in tomato’s relatives. The group mainly including potato, pepper, eggplant and petunia, is the world’s most important vegetable plant family in terms of both economic value and production volume. The availability of tomato genome sequence will not only serve as a reference for other Solanaceous species but also help in comparative genomics among diverse taxa.

TGC was established as a result of a scientific conference organized in 2003in Washington, DC.Consortium members include scientists from Argentina, Belgium, China,France, Germany, India, Israel,Italy,Japan, Korea,Spain, the Netherlands, the United Kingdom and the United States. The genome sequence and related resources can be accessed at the Solgenomics website (

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Researchers at the Institute of High Energy Physics (IHEP) recently developed a two dimensional X-ray detector with a high counting rate for X-ray and a high high position resolution for detection.

The two dimensional X-ray facility adopts 200mm×200mm gas electron multiplier (GEM) as the main detecting device. GEM develops vigorously in China due to its simple structure and excellent performance, and wide use in many fields.

After years of research, scientists have mastered manufacturing techniques of related detectors, settled key problems in electrode structure design, and developed fast readout front-end electronics with multi-channels.

Apart from satisfying the users' needs at sychrotron radiation facility, this newly delveped detector can be widely applied to x-ray diffraction, small-angle scattering and imaging.

Experts concluded at a review meeting held at IHEP that all the designed specifications were satisfactorily met.

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Indocyanine green (ICG) is a near-infrared (NIR) fluorescence dye for extensive biological application. It is the only NIR organic dye approved by the U.S. Food and Drug Administration (FDA) for human medical imaging and diagnosis. However, ICG has several challenges in imaging application, such as poor aqueous stability, concentration-dependent aggregation, rapid elimination from the body, and lack of target specificity.

To overcome these limitations, Dr CAI Lintao’s group, from Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences (SIAT), designed and developed the biodegradable tumor targeting nanoprobes (FA-ICG-PLGA-lipid NPs). They used a single-step self-assemble and nanoprecipitation method to prepare the folate receptor-targeted nanoprobes. The nanoprobes exhibited good biocompatibility, significant stability and specific tumor targeting. These biodegradable NIR nanoprobes provided new opportunities in tumor diagnosis and biomedical imaging field.

The research results have been published online on May 9 in Biomaterials (

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). This work was supported by National Basic Research Program of China (973 program), National Natural Science Foundation of China, “Hundred Talents program” of Chinese Academy of Sciences, Science and Technology Key Project of Guangdong and Shenzhen Key Laboratory of Cancer Nanotechnology.

The research group led by CAI carries out the cutting-edge nanomedicine research in the development of multifunctional and nanostructured composite materials, providing highly sensitive and selective detection method through molecular probes for medical imaging and molecular diagnosis at nanoscale and single molecular level, exploring new device concepts and self-assembly techniques for biosensing, environmental monitoring, and biomedical applications.

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From May 15 to 19, the 3rd China Satellite Navigation Conference (aka Beidou Conference) was held in Guangzhou. The theme of this year's conference is "Beidou on the path of application". Accelerating the commercial application of the Beidou Navigation Satellite System has become the center of attention of the industry.

"The independence and compatibility of the structure of the Beidou system, its integration of positioning and communication, enhanced features, and construction-application policy will usher in the best development phase for its industrial application", said academician Sun Jiadong, chief designer of the Beidou Navigation Satellite System project and president of Science Committee of the Beidou Conference. Mr. Sun suggested that the rapid development of internet and information technology and the modern business models had promoted the reform of social economic pattern and the information industry; it had also provided all kinds of possibilities for the application and innovation of satellite navigation.

Good prospects for the civil market

"The contribution rate of the Beidou Navigation Satellite System to the global navigational precision, stability, and reliability is as high as 23.6 percent", new data released by Yang Yuanxi, academician of the Chinese Academy of Sciences, during the conference. He believes that, in comparison with the USA's GPS, Beidou is superior in terms of initial positioning speed and time service precision. After the completion of the network connection of the Beidou Navigation Satellite System, users positioning, text communication, and position report would take only seconds, whereas the initial positioning of GPS would take 1 to 3 minutes. In the future, Beidou aims to take up 80 percent of the Chinese market, and endeavor to gain 20 percent of the global market.

According to Liu Jingnan, academician of Chinese Academy of Engineering, early testing shows that the availability of GPS in China and the Asian-Pacific region is around 60 percent, and the availability of Beidou + GPS would reach 80 percent. Besides, experiments have proved that after adding the Beidou system, navigational precision in the Asian-Pacific region would increase by 10 to 20 percent.

As the network connection of Beidou approaches completion, China's Beidou Navigation Satellite System is currently incubating a huge market. According to the prediction of CCID Consulting, the scale of China's Beidou satellite navigation industry will amount to RMB 30.346 billion Yuan in 2014, the compound annual growth rate in the next 3 years being as high as 52.3 percent. A Chinese Beidou Satellite Navigation industry union predicts that the Beidou Navigation Satellite industry will reach RMB 50 billion Yuan in 2015. In the few years to come, the annual growth rate of the Beidou Navigation Satellite industry will be over 50 percent, or even over 60 percent, with demands in the civil market increasing steadily.

Get through the industrial chain

The innovative model of "products + service" was a major highlight of this year's Beidou Conference. In the conference, UniStrong, Hwa Create Corporation, Guangzhou Haige Communications Group, EVE Energy and other enterprises have all exhibited their new products, including such core parts and terminal products as dual systems (Beidou/GPS) positioning modules, dual systems board (including satellite reception and high-precision time service), dual systems in-car navigation terminals and hand-held devices, Beidou combined navigation modules, and Beidou terminals and equipments that cater to different industrial application. Their intentions to grab the application market of the Beidou system seem rather obvious.

Presently, the biggest issue facing the Beidou satellite navigation industry is the price of terminal products. Technically and theoretically Beidou has such advantages as positioning precision and two-way transmission over GPS, but the price of its terminal products is markedly higher. In this year's conference, UniStrong introduced a Beidou navigation module that was priced at RMB 199 Yuan, which could reduce the price of Beidou's core part by as much as 70 percent.

Industrial participants point out that the commercialization of Beidou must not depend too much on government subsidy. Beidou needs to be energetic, and the price must be similar to GPS. Only this way can users really come to accept Beidou.

"The Beidou System belongs to us. We all have the willingness to use it, but in order to make users truly accept Beidou, the key is to offer high-performance products at a price that is the same as that of GPS, offering GPS + Beidou products, that is, providing users with an extra choice but without increasing the cost", said Xie Haizhong, chief manager of UniStrong's Beidou Navigation Technology, "The keys for the application of Beidou: firstly, the Beidou system needs to be stable and reliable, which is even more important than the system's having high performance; secondly, the performance of terminal products that end up in the hands of users must be stable and reliable; and thirdly, and most importantly, the use of Beidou must not increase the users' cost; price is an important factor. As an enterprise that promotes industrial application, what we can do is the last two things: stable and reliable products and reasonable price. If we can do these well, the industry will naturally get better".

In fact, from the perspective of industrial chain, besides high-quality and cost-effective products, the Beidou Navigation Satellite System also needs manufacturing enterprises to come up with competitive solutions and promotion strategies creatively. This is also essential for the large-scale development of Beidou.

Introducing service platforms

Also appearing in the conference was the Beidou Online service platform introduced by Beidou Star. It is learned that Beidou Online is a comprehensive service platform that is supported by such technologies as the internet of automobiles, cloud computing, satellite navigation, and mobile internet, is based on the Beidou Navigation Satellite System, and provides position information of automobiles to government and industries through Beidou navigation products. In the future, Beidou Online will gradually develops into a large-scale Beidou internet of automobiles operation service center that is open to the whole country and covers industrial and consumption users.

Realizing that innovation of business model is an important propeller for the commercialization of Beidou, UniStrong has launched the "China Position" service platform in as early as July, 2011, which has promoted the integration of Beidou with other satellite navigation systems and the integration of the 3S (satellite navigation, geography information system, and remote sensing) technologies with IT, internet and other industries, effectively transferring positioning service contents to the vast consumption market. It is told that, within one year of its launching, the "China Position" service platform has been widely used in such fields as auto clubs, telecommunication, logistics, and civil administration.

Industrial participants who took part in the conference point out that, from the perspective of the industrial chain, China's Beidou Navigation Satellite System has now basically possessed the entire industrial chain from chip manufacturing, navigation maps, and terminal to system integration and operation service. However, the commercialization of the Beidou Navigation Satellite System needs not only to be pushed by products of high performance-price ratio, but also to be driven by market demands.

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Surface Plasma Resonance (SPR) spectroscopy technology has been widely used in various areas, such as reaction dynamics investigation, biochemical sensors, electrode/electrolyte interface characterization, kinetic parameters determination, and biomolecular interactions investigation, etc. The Changchun Institute of Applied Chemistry (CIAC) scientists recently developed the electrochemical associated time-resolved surface plasma resonance spectroscopy (EC-SPR) with independent intellectual property rights successfully.

From 2009, the researchers have been devoted to developing new electrochemical sensors, detectors and electrochemical associated equipments. During the three years’ investigation, the research group realized high sensitivity, fast response, long life and dynamical online testing of the technology. They combined the electrochemical techniques with optical array detector with high time-resolution, and applied to the surface plasma resonance analysis detection. The matched software programs were updated as well.

For this novel designed EC-SPR spectroscopy, by using the two-pixel optical position sensor array, the response time of the SPR spectral measurement has been greatly shortened. The new method can be applied to investigations of the adsorption reaction kinetics of the small molecules on the interface and measurements of the small molecules interactions. This EC-SPR spectroscopy combined a variety of transient and steady-state electrochemical techniques together. For example, the combinations of differential pulse, chronoamperometry square wave voltammetry method and other transient electrochemical methods with SPR spectroscopy were the original creation and internationally unique.

This innovation and creation not only broadened the application scope of SPR detection method, but also realized the SPR testing during the high-speed electrochemical modulation process.

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Researchers from Changchun Institute of Applied Chemistry (CIAC) claim to have made it possible to detect various toxic substances more effectively, and the method is believed to be a sensitive, rapid, reproducible and economic alternative for toxicity screening of chemicals and environmental water monitoring, especially advantageous for in situ monitoring of water system.

There have been considerable attempts to develop technologies in this field. Researchers have found that identification and quantization of the pollutant concentrations in aquatic environment is relatively easy, however, providing indication of these chemicals on bioavailabilities still needs deep investigation. To solve this problem, bioassay has been introduced to fully assess the impacts of toxicity on biota, after which, many tests were carried out to monitor toxicity levels of compounds present in water incorporate representatives from plants, invertebrates and fish as the sensing agents. But one of the big problem existing is, many of these tests are too time-consuming.

YONG Daming, and colleagues from CIAC, has come up with a way of tackling this problem. They developed a mediated method by using ferricyanide under non-deaerated condition for biotoxicity, which does not require air supply or deaerated equipment for rapid measuring of real polluted wastewater. In their study, Ultramicroelectrode array was employed for effectively amplify the electrochemical signal from the total limiting currents to distinguish a little change in toxicity. Comparison with the results reported previously has confirmed that the present strategy is more simple, operatable and economic.

The research findings have been published in Analytica Chimica Acta 701 (2011) 164– 168, and this project was supported by the National Basic Research Program of China (973 program, 2010CB933600), and the National Natural Science Foundation of China (20820102037, 20935003).

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