Determination of glass transition temperature using temperature dependent signal from a cryogenic photopyroelectric instrument

•A photopyroelectric device for 90 K to ambient thermal studies was constructed.•Temperature controlled LED was used to heat the sensor/sample interface.•The thermal diffusion equations for FPPE configuration were solved.•Sensor used was LiTaO3 with an ITO layer on one side and gold on other.•The glass transition temperature was obtained directly from the effusivity. Herein, we report the construction of a low temperature photo pyroelectric (PPE) instrument using which the glass transition temperature (Tg) of a well known glass former (glycerol) is determined via temperature dependent PPE signal. Havriliak Negami (HN) model was used to analyze the PPE signal. As expected, relaxation time for glycerol follows Vogel Fulcher Tammann (VFT) model. The Tg was determined from the HN and VFT parameters. Obtained results were compared with previously published data.