@misc{IngenboschQuintDyllickBrenzingeretal., author = {Ingenbosch, Kim N. and Quint, Stephan and Dyllick-Brenzinger, Melanie and Wunschik, Dennis S. and Kiebist, Jan and S{\"u}ss, Philipp and Liebelt, Ute and Zuhse, Ralf and Menyes, Ulf and Scheibner, Katrin and Mayer, Christian and Opwis, Klaus and Gutmann, Jochen S. and Hoffmann-Jacobsen, Kerstin}, title = {Singlet oxygen generation by peroxidases and peroxygenases for chemo-enzymatic synthesis}, series = {ChemBioChem}, volume = {22}, journal = {ChemBioChem}, number = {2}, issn = {1439-7633}, doi = {10.1002/cbic.202000326}, pages = {398 -- 407}, abstract = {Singlet oxygen is a reactive oxygen species undesired in living cells but a rare and valuable reagent in chemical synthesis. We present a fluorescence spectroscopic analysis of the singlet-oxygen formation activity of commercial peroxidases and novel peroxygenases. Singlet-oxygen sensor green (SOSG) is used as fluorogenic singlet oxygen trap. Establishing a kinetic model for the reaction cascade to the fluorescent SOSG endoperoxide permits a kinetic analysis of enzymatic singlet-oxygen formation. All peroxidases and peroxygenases show singlet-oxygen formation. No singlet oxygen activity could be found for any catalase under investigation. Substrate inhibition is observed for all reactive enzymes. The commercial dye-decolorizing peroxidase industrially used for dairy bleaching shows the highest singlet-oxygen activity and the lowest inhibition. This enzyme was immobilized on a textile carrier and successfully applied for a chemical synthesis. Here, ascaridole was synthesized via enzymatically produced singlet oxygen.}, language = {en} } @misc{StrobelAlvaradoChavarinVoelkeletal., author = {Strobel, Carsten and Alvarado Chavarin, Carlos and V{\"o}lkel, Sandra and Jahn, Andreas and Hiess, Andre and Knaut, Martin and Albert, Matthias and Wenger, Christian and Steinke, Olaff and Stephan, Ulf and R{\"o}hlecke, S{\"o}ren and Mikolajick, Thomas}, title = {Enhanced Electrical Properties of Optimized Vertical Graphene-Base Hot Electron Transistors}, series = {ACS Applied Electronic Materials}, volume = {5}, journal = {ACS Applied Electronic Materials}, number = {3}, issn = {2637-6113}, doi = {10.1021/acsaelm.2c01725}, pages = {1670 -- 1675}, abstract = {The arrival of high-mobility two-dimensional materials like graphene leads to the renaissance of former vertical semiconductor-metal-semiconductor (SMS) hot electron transistors. Because of the monolayer thickness of graphene, improved SMS transistors with a semimetallic graphene-base electrode are now feasible for high-frequency applications. In this study we report about a device that consists of amorphous silicon, graphene, and crystalline silicon. For the first time, this device is fabricated by a four-mask lithography process which leads to significant improvements in the device performance. A strongly increased common-emitter current gain of 2\% could be achieved while the on-off ratio improved to 1.6 × 105, which is already higher than predicted theoretically. This could be mainly attributed to better interface characteristics and decreased lateral dimensions of the devices. A cutoff frequency of approximately 26 MHz could be forecasted based on the DC measurements of the device.}, language = {en} }