We numerically study Joule heating in a THz emitter made of
Bi2Sr2CaCu2O8 + δ
(Bi2212) single crystal with its CuO planes oriented perpendicular to supporting substrate. The
single crystal is glued to the substrate by a layer of PMMA. The electrical current is applied in the
c-axis direction across many intrinsic Josephson junctions (IJJ’s) in Bi2212. The
calculations show that the internal temperature increases to an acceptable 10–20 K only above the bath temperature for a Joule power density of ∼ 105 W cm − 3
typical for experiments on THz emission from IJJ’s. This makes the suggested geometry
promising for boosting the output power of the emitter.