Project Details
Projekt
Flexible Graphene-Base Heterojunction Transistor for Several Hundred Gigahertz Operation
Subject Area
Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering
Term
from 2015 to 2024
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 273132745
In this project we will investigate a new vertical transistor concept fabricated on flexible substrates. Graphene is used as an extremely thin, low resistivity base electrode. The graphene base heterojunction transistor (GBHT) can be thought of as a NPN bipolar transistor with the p-type base being replaced by a graphene layer. This novel concept is based on a vertical arrangement of emitter, base, and collector. The device is obtained by stacking an n-type semiconductor (emitter), a graphene monolayer (base), and another n-type semiconductor (collector).The band scheme, working principle and additional advantages of this novel transistor concept have been explained in detail in the proposal of the previous project (DFG BA 2009/6-1 and WE3594/5-1). In the proposed transistor configuration on flexible substrates with n-type hydrogenated amorphous silicon (a-Si:H), frequencies up to several 100 GHz should be feasible, because the cut-off frequency is mainly controlled by the mobility of a-Si:H. To our knowledge, we are the only group worldwide so far working on this promising unique device concept. This pioneering work will potentially pave the way for a new class of electronic devices with graphene in general.The receiver and transmission circuits are the fundamental elements of wireless communications. Based on simulation results, a high frequency oscillator can be envisioned as a first application. Using the variable capacitance of the a-Si:H / graphene diodes, a varactor device could be integrated to implement the design as a voltage controlled oscillator. This approach could enable the first building block on flexible substrates.
DFG Programme
Priority Programmes
Subproject of
SPP 1796:
High Frequency Flexible Bendable Electronics for Wireless Communication Systems (FFLexCom)
Co-Investigators
Dr.-Ing. Matthias Albert; Dr. Mindaugas Lukosius
