A novel high step-down non-isolated DC-DC converter has been proposed. The proposed converter consists of highly efficient non-isolated cell converters using bidirectional semiconductor power devices, and these cell c...A novel high step-down non-isolated DC-DC converter has been proposed. The proposed converter consists of highly efficient non-isolated cell converters using bidirectional semiconductor power devices, and these cell converters are connected in ISOP (input series and output parallel). The non-isolated ISOP converter achieves high step-down ratio of D/N, operating N cell converters under the duty ratio olD. Availability of the proposed converter has been shown by developing the 48 V-12 V laboratory prototype using two 24 V-12 V cell converters. Design consideration for the 48 V-3 V multicellular converter using four 12 V-3 V cell converters has been also conducted, and the potential to approach the efficiency of 97% has been discussed. The proposed topology is suitable for the POL (point of load) converters in the highly efficient next generation DC distribution system for data centers.展开更多
Organic phototransistors (OPTs) have been intensively studied in recent years due to the combined ad- vantages of phototransistors and organic semiconductors (OSCs). However, the electrical performance of OPTs is ...Organic phototransistors (OPTs) have been intensively studied in recent years due to the combined ad- vantages of phototransistors and organic semiconductors (OSCs). However, the electrical performance of OPTs is lar- gely limited by OSCs themselves, posing a challenge to further improve the performance of the devices. Preparing nano/mi- cro-structures of OSCs is considered as an effective way to improve the performance of OPTs. Polystyrene (PS) micro- sphere, as a kind of insulating and low-cost material, is ex- tensively used in fabricating nano/microporous structures, and the resulting devices exhibit high response to external stimuli. Therefore, we combined PS microspheres with OSCs to fabricate PS/OSC OPTs, and the Ilight/Idark ratio was en- hanced by two orders of magnitude compared with the pris- tine counterparts, which can be modulated from 46 to 1800 by controlling the diameters of PS microsphereso This strategy paves a way for developing high-performance OPTs with nano/microporous structures with potential applications in organic optoelectronics.展开更多
文摘A novel high step-down non-isolated DC-DC converter has been proposed. The proposed converter consists of highly efficient non-isolated cell converters using bidirectional semiconductor power devices, and these cell converters are connected in ISOP (input series and output parallel). The non-isolated ISOP converter achieves high step-down ratio of D/N, operating N cell converters under the duty ratio olD. Availability of the proposed converter has been shown by developing the 48 V-12 V laboratory prototype using two 24 V-12 V cell converters. Design consideration for the 48 V-3 V multicellular converter using four 12 V-3 V cell converters has been also conducted, and the potential to approach the efficiency of 97% has been discussed. The proposed topology is suitable for the POL (point of load) converters in the highly efficient next generation DC distribution system for data centers.
基金supported by the National Natural Science Foundation of China (51741302, 51603151 and 51373123)the National Key Research and Development Program of China (2017YFA0103900 and 2017YFA0103904)+1 种基金Science and Technology Foundation of Shanghai (17JC1404600)the Fundamental Research Funds for the Central Universities
文摘Organic phototransistors (OPTs) have been intensively studied in recent years due to the combined ad- vantages of phototransistors and organic semiconductors (OSCs). However, the electrical performance of OPTs is lar- gely limited by OSCs themselves, posing a challenge to further improve the performance of the devices. Preparing nano/mi- cro-structures of OSCs is considered as an effective way to improve the performance of OPTs. Polystyrene (PS) micro- sphere, as a kind of insulating and low-cost material, is ex- tensively used in fabricating nano/microporous structures, and the resulting devices exhibit high response to external stimuli. Therefore, we combined PS microspheres with OSCs to fabricate PS/OSC OPTs, and the Ilight/Idark ratio was en- hanced by two orders of magnitude compared with the pris- tine counterparts, which can be modulated from 46 to 1800 by controlling the diameters of PS microsphereso This strategy paves a way for developing high-performance OPTs with nano/microporous structures with potential applications in organic optoelectronics.