Low-temperature GaSb bolometer for non-equilibrium phonon pulse detection

We report on the first use of undoped bulk-grown p-type GaSb as a low-tempe rature detector in composite bolometers for the detection of non-equilibriu m phonons. In the ohmic regime, the detector's low-temperature resistivity measurements are consistent with the Mott variable-range hopping conduction characterized by In R(T) proportional to exp(T-0/T)(1/4) with a temperatur e coefficient of (-0.42 - 3.46 ln T)(-1) K-1 in the temperature range 1.4 K less than or equal to T less than or equal to 4.2 K. The detector showed a fast response time of approximately 1 mus and excellent reproducibility. I n our opinion, the most promising areas of applications are in nuclear spec troscopy (low-energy x-ray and beta-particle detection) for which small-vol ume detectors can be used and the study of phonon dynamics in 2DEG structur es.