Thermowave Studies of Porous Silicon as Substrate Material for Pyroelectric Detectors

摘要

For the purpose of investigating the thermophysical characteristics of porous silicon (por-Si) photopyroelectric and photoacoustic studies have been performed. The main thermal parameters of por-Si, namely the volume heat capacity C_T, thermal conductivity K_T, thermal diffusivity a_T= K_T/C_T and effusivity b_T = (K_T C_T)~(1/2), thermal contrast factor, coefficients of thermal wave reflection and transmission at the boundary por-Si layer Si-substrate arid also for LiNbO_3-Si-substrate and LiNbO_3-por-Si-substrate have been evaluated. Efficiency of placing the pyroactive or bolometric sensitive elements of thermal detectors of radiation on the por-Si layer (with a relative low value of b_T) on Si-substrate under operation at low frequencies of flux modulation for radiation fluxes of low power has been shown.