Graphene bolometer for vis-IR spectral range made on nano-SiN membrane

A sensitive bolometric detector for visible and infrared wavelengths based on a novel assembly principle of a graphene monolayer on a nano/micro SiN membrane is realised. The basic operating principle of the optical detector relies on the absorption of electromagnetic radiation in the graphene and creation of a strong thermal gradient, rT, which is detected via the Seebeck effect: Voltage = S x ∇rT, where S is the Seebeck coefficient of graphene. A simple lithography-free deposition of two metal contacts with different electron work functions: Pd (by sputtering) and Ag (by jet printing and annealing) was used. Sensitivity of the bolometer was the same ~1:1 mV/mW at 1030 and 515 nm wavelengths.