The contributions of the acoustic modes and optical modes to the primary pyroelectric coefficient of GaN

Abstract

As competitive next generation pyroelectric sensors, the pyroelectricity of GaN has been investigated. The specific heat of the wurtzite GaN is calculated from the Raman-scattering data. The contributions of the acoustic modes and optical modes to the primary pyroelectric coefficient of GaN are calculated from 0 to 600 K. An explicit expression of the primary pyroelectric coefficient as a function of temperature is derived. It is found that the primary pyroelectric coefficient of GaN can be expressed as the sum of the Debye function and Einstein function. It is substantially different from that of conventional ferroelectrics-based pyroelectric devices which can be described only by the Einstein function.