Graphene bolometer with thermoelectric readout and capacitive coupling to an antenna

Abstract

We report on a prototype graphene radiation detector based on the thermoelectric effect. We used a split top gate to create a p-n junction in the graphene, thereby making an effective thermocouple to read out the electronic temperature in the graphene. The electronic temperature is increased due to the AC currents induced in the graphene from the incoming radiation, which is first received by an antenna and then directed to the graphene via the top-gate capacitance. With the exception of the constant DC voltages applied to the gate, the detector does not need any bias and is therefore very simple to use. The measurements showed a clear response to microwaves at 94 GHz with the signal being almost temperature independent in the 4–100 K temperature range. The optical responsivity reached ∼700 V/W.

Large Responsivity of Graphene Radiation Detectors with Thermoelectric Readout: Results of Simulations

“…These estimations are also in agreement with the recent experimental works on TEP readout, e.g. [4,20,21].…”

“…Also, the contact resistance can be effectively reduced by increasing the perimeter of contact even for a non-encapsulated graphene [32]. Finally, the capacitive coupling of antennas to graphene, where the contact resistance does not play any role for the open-circuit TEP readout, has recently been realized [21].…”

Nanodevices at terahertz frequency based on 2D materials

“…Following the first demonstrations of antenna coupled overdamped plasma wave photodetectors operating in the resistive self mixing regime [25,26], several architectures have been proposed and implemented including graphene bolometers [27], ballistic rectifiers [28], and fast photo-thermoelectric sensors [22,24,29]. Recently, a novel THz thermoelectric sensor based on high-mobility, hBN-encapsulated graphene, have been implemented, involving a combination of a small-area graphene pn-junction and an H-shaped antenna that focuses the incident THz radiation onto a small active area.…”

The Role of <i>Pτ</i> in the Photothermoelectric Effect and in Photoredox Catalysis Reactions

“…Accordingly, we review the data published by Lu et al [2]. In addition, we treat the r-STO PTE photodetector as a capacitor with capacitance C, similarly to the treatment given to thermoelectric devices in [1] and [5] due their multi-layer structure alternating conducting and non-conducting elements.…”

“…[5]. Finally, we explain the anomaly for the device illuminated with light at 1550 nm λ = as consequence of the sample preparation.…”