TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Knaut, Martin A1 - Völkel, Sandra A1 - Albert, Matthias A1 - Hiess, Andre A1 - Max, Benjamin A1 - Wenger, Christian A1 - Kirchner, Robert A1 - Mikolajick, Thomas T1 - High Gain Graphene Based Hot Electron Transistor with Record High Saturated Output Current Density T2 - Advanced Electronic Materials N2 - Hot electron transistors (HETs) represent an exciting frontier in semiconductor technology, holding the promise of high-speed and high-frequency electronics. With the exploration of two-dimensional materials such as graphene and new device architectures, HETs are poised to revolutionize the landscape of modern electronics. This study highlights a novel HET structure with a record output current density of 800 A/cm² and a high current gain α, fabricated using a scalable fabrication approach. The HET structure comprises two-dimensional hexagonal boron nitride (hBN) and graphene layers wet transferred to a germanium substrate. The combination of these materials results in exceptional performance, particularly in terms of the highly saturated output current density. The scalable fabrication scheme used to produce the HET opens up opportunities for large-scale manufacturing. This breakthrough in HET technology holds promise for advanced electronic applications, offering high current capabilities in a practical and manufacturable device. KW - Graphene KW - Transistor Y1 - 2024 U6 - https://doi.org/10.1002/aelm.202300624 SN - 2199-160X VL - 10 IS - 2 ER - TY - GEN A1 - Strobel, Carsten A1 - Alvarado Chavarin, Carlos A1 - Völkel, Sandra A1 - Jahn, Andreas A1 - Hiess, Andre A1 - Knaut, Martin A1 - Albert, Matthias A1 - Wenger, Christian A1 - Steinke, Olaff A1 - Stephan, Ulf A1 - Röhlecke, Sören A1 - Mikolajick, Thomas T1 - Enhanced Electrical Properties of Optimized Vertical Graphene-Base Hot Electron Transistors T2 - ACS Applied Electronic Materials N2 - 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. KW - Graphene KW - Transistor Y1 - 2023 U6 - https://doi.org/10.1021/acsaelm.2c01725 SN - 2637-6113 VL - 5 IS - 3 SP - 1670 EP - 1675 ER -