Terahertz Sensing with Golay cells microarray device

The THz radiation is a part of the electromagnetic spectrum between microwaves and infrared. When described as made of photons, their quantum of energy is lower than kBT at room temperature, and the strategies used in photon detection cannot be applied. When described in terms of high-frequency EM waves, the associated electron velocity in a material is faster than any known material. So the strategies used to generate or detect the radiofrequency cannot be applied. Hence, the use of the term THz gap to denote the lack of resources in a field that has otherwise many potential applications. Among the incoherent detectors commercially available in the market, the Golay cell is one of the most sensitive thermal detectors, however, its design remained practically unchanged since its invention in 1947. The advent of new technologies and materials like graphene could allow the breakthrough needed to innovate this detector and partially close the gap. Unfortunately, many practical limitations hindered its development towards application on the microscale. In this work, I aim to develop a fabrication method for the efficient sealing and enclosure of an array of micrometer-scale cells with an ultrathin membrane. The membrane is composed of CVD single-layer graphene and a reinforcing nm-thin titanium layer. A back-side sealing is provided by a silicone rubber cork: the two-side sealing allows the transfer of mm-sized membranes avoiding the problems arising during the membrane transfer from solution. These water- and gas-tight cells could be used for all those applications that require the efficient sealing of a wide variety of liquids and gases, such as the Golay cells. Throughout this thesis, I also explore different modifications of the membrane to improve its applicability into other fields, in particular improving its transparency to the photoelectron emitted in XPS analysis and proving its potential application in ultrahigh vacuum applications. Finally, I will demonstrate the feasibility of the sealed arrays as Golay cells detecting the THz radiation emitted by a Globar source.