Thermal Conductivity of Amorphous Silicon

Abstract

We measured the thermal conductivity of amorphous silicon using a new simple steady state method implementing deposited Pt stripes as both resistive heaters and temperature monitors. Amorphous Si films were sputtered on Si substrates and heat was injected through the Pt resistive heaters. The increase in heater temperature was determined by the temperature-dependent electrical resistance of the Pt stripes. We thus determined the thermal conductivity of a-Si at room temperature to be 1.8 W/m·K, which is about one-hundredth of that of crystal Si. This information is very important to properly design the thermal resistance of long-wavelength surface emitting lasers which use the a-Si in high-reflective stack mirrors.