CdS : SiO2 nanocomposite as a luminescence-based wide range temperature sensor

Abstract

A wide range (20–560 K) temperature sensor is devised for the first time from CdS : SiO₂ nanocomposite thin films grown by pulsed laser deposition. Highly intense, stable, and broad red emission observed from the CdS : SiO₂ nanocomposite is employed to obtain a luminescence thermometer. Nearly monodisperse and small sized CdS nanocrystals (∼3 nm) in a SiO₂ matrix, as viewed by transmission electron microscopy, may be accountable for the absence of band edge emission even at 20 K. The sensor exhibits almost linear behavior in all cryogenic, physiological, and high temperature ranges. The average sensitivity and resolution of the sensor reported here were ≈10⁻² K⁻¹ and 10⁻⁴ K, respectively, with a maximum relative sensitivity of ∼8.4% K⁻¹ at 120 K.