Graphene-Base Heterojunction Transistor: An Attractive Device for Terahertz Operation

Graphene base heterojunction transistor: An explorative study on device potential, optimization, and base parasitics

“…A comparison between a n-type Si GBHT and an optimized SiGe HBT structure is then carried out in order to estimate the potential advantage of the new device. The effect of the graphene base parasitics on the unity power gain frequency f max of Si GBHTs is finally estimated, further extending the work carried out in [15].…”

“…In our previous work [15], only h1 0 0i-Si GBHTs were simulated: since in general the tunneling component of the device current is not negligible, it is recommendable to study all the main crystallographic orientations, characterized by different effective masses. Besides, silicon is not necessarily the best semiconductor choice for the emitter/collector layers, also considering the technological problems related with the graphene interface [17][18][19].…”

“…In order to overcome the GBT limitations, in [15] we have investigated a new transistor architecture with graphene base, named graphene-base heterojunction transistor (GBHT). The GBHT is obtained by simply stacking an n-type semiconductor layer (emitter), a graphene monolayer (base), and another n-type semiconductor layer (collector).…”

Electrical Compact Modeling of Graphene Base Transistors

“…Hence, the choice of the material used for the EBi and BCi region is of major importance. EBi and BCi can be either an insulator material such as SiO2 or high-k dielectrics to exploit a tunneling transport [6] or a semiconductor such as Ge or Si to foster a thermionic current [12]. According to the transistor structure (see Figure 1), the following equivalent circuit is proposed (see Figure 2).…”

“…At high injection, an additional charge K Q Δ [9,12], with respect to QDE appears when the transfer current ICE overpass the critical current ICK:…”